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UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 10-K

(Mark One)

For the fiscal year ended December 31, 2011

OR

For the transition period from              to             

Commission file number 001-33264

U.S. AUTO PARTS NETWORK, INC.

(Exact Name of Registrant as Specified in Its Charter)

16941 Keegan Avenue, Carson, CA 90746

(Address of Principal Executive Offices) (Zip Code)

Registrant’s Telephone Number, Including Area Code: (310) 735-0085

Securities registered pursuant to Section 12(b) of the Act:

Securities registered pursuant to Section 12(g) of the Act: None

Indicate by check mark if the registrant is a well-known seasoned issuer, as defined in Rule 405 of the Securities Act.    Yes  ¨    No  x

Indicate by check mark if the registrant is not required to file reports pursuant to Section 13 or Section 15(d) of the Act.    Yes  ¨    No  x

Indicate by check mark whether the registrant (1) has filed all reports required to be filed by Section 13 or 15(d) of the Securities Exchange Act of 1934 during the preceding 12 months (or for such shorter period that the registrant was required to file such reports), and (2) has been subject to such filing requirements for the past 90 days.    Yes  x    No  ¨

Indicate by check mark whether the registrant has submitted electronically and posted on its corporate Website, if any, every Interactive Data File required to be submitted and posted pursuant to Rule 405 of Regulation S-T (§232.405 of this chapter) during the preceding 12 months (or for such shorter period that the registrant was required to submit and post such files).    Yes  x    No  ¨

Indicate by a check mark if disclosure of delinquent filers pursuant to Item 405 of Regulation S-K is not contained herein, and will not be contained, to the best of registrant’s knowledge, in definitive proxy or information statements incorporated by reference in Part III of this Form 10-K or any amendment to this Form 10-K.  x

Indicate by check mark whether the registrant is a large accelerated filer, an accelerated filer, or a non-accelerated filer, or a smaller reporting company. See the definitions of “large accelerated filer,” “accelerated filer,” and “smaller reporting company” in Rule 12b-2 of the Exchange Act. (Check one):

Indicate by check mark whether the registrant is a shell company (as defined in Exchange Act Rule 12b-2).    Yes  ¨    No  x

The aggregate market value of the common stock held by non-affiliates of the registrant as of July 2, 2011 was approximately $112,924,090 (based on the closing sales price of the registrant’s common stock on that date). For the purposes of this calculation, shares owned by officers, directors and 10% stockholders known to the registrant have been deemed to be owned by affiliates. This determination of affiliate status is not necessarily a conclusive determination for other purposes.

As of March 19, 2012, there were 30,645,764 shares of the registrant’s common stock outstanding.

DOCUMENTS INCORPORATED BY REFERENCE

Portions of our proxy statement for the 2012 Annual Meeting of Stockholders (the “Proxy Statement”) are incorporated by reference in Part III hereof. Except with respect to information specifically incorporated by reference in this Form 10-K, the Proxy Statement is not deemed to be filed as a part hereof.

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U.S. AUTO PARTS NETWORK, INC.

ANNUAL REPORT ON FORM 10-K

FOR THE FISCAL YEAR ENDED DECEMBER 31, 2011

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Unless the context requires otherwise, as used in this report, the terms “U.S. Auto Parts,” the “Company,” “we,” “us” and “our” refer to U.S. Auto Parts Network, Inc. and its subsidiaries.

U.S. Auto Parts^®, U.S. Auto Parts Network™, PartsTrain^®, Partsbin™, Kool-Vue™, Auto-Vend™, JC Whitney^® , and Stylintrucks^TM, amongst others, are our United States trademarks. All other trademarks and trade names appearing in this report are the property of their respective owners.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

The statements included in this report, other than statements or characterizations of historical or current fact, are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended (the “Securities Act”) and Section 21E of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and we intend that such forward-looking statements be subject to the safe harbors created thereby. Any forward-looking statements included herein are based on management’s beliefs and assumptions and on information currently available to management. We have attempted to identify forward-looking statements by terms such as “anticipates,” “believes,” “could,” “estimates,” “expects,” “intends,” “may,” “plans,” “potential,” “predicts,” “projects,” “should,” “will,” “would”, “will likely continue,” “will likely result” and variations of these words or similar expressions. These forward-looking statements include, but are not limited to, statements regarding future events, our future operating and financial results, financial expectations, expected growth and strategies, current business indicators, capital needs, capital deployment, liquidity, contracts, litigation, product offerings, customers, acquisitions, competition and the status of our facilities. Forward-looking statements, no matter where they occur in this document or in other statements attributable to the Company involve known and unknown risks, uncertainties and other factors that may cause our actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. We discuss many of these risks in greater detail under the heading “Risk Factors” in Part I, Item 1A of this report. Given these uncertainties, you should not place undue reliance on these forward-looking statements. You should read this report and the documents that we reference in this report and have filed as exhibits to the report completely and with the understanding that our actual future results may be materially different from what we expect. Also, forward-looking statements represent our management’s beliefs and assumptions only as of the date of this report. Except as required by law, we assume no obligation to update these forward-looking statements publicly, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if new information becomes available in the future.

PART I

Overview

We are one of the leading online sources for automotive aftermarket parts and repair information. Our vision is that vehicle owners never overpay for service and repair. Our mission is to be the service and repair advocate for vehicle owners, to increase their confidence in the repair process, and to provide the most affordable option for their service and repair needs.

We principally sell our products, identified as stock keeping units (“SKUs”), to individual consumers through our network of websites and online marketplaces. Our user-friendly websites provide customers with a comprehensive selection of approximately 2 million SKUs with detailed product descriptions and photographs. We have developed a proprietary product database that maps our SKUs to product applications based on vehicle makes, models and years.

Our online sales channel and relationships with suppliers enable us to eliminate several intermediaries in the traditional auto parts supply chain and offer a broad selection of SKUs. Additionally, as an online retailer, we believe greater economies of scale can be achieved online than in brick and mortar stores.

We were incorporated in Delaware in 1995 as a distributor of aftermarket auto parts and launched our first website in 2000. Since then, we have continued to expand our online operations, increasing the number of SKUs sold through our e-commerce network, adding additional websites, improving our internet marketing proficiency, and commencing sales on online marketplaces. In October 2008, we acquired AutoMD.com for the purpose of developing content and a user community to educate consumers on maintenance and service of their vehicles.

In August 2010, we acquired all of the issued and outstanding shares of Automotive Specialty Accessories and Parts, Inc. and its wholly-owned subsidiary Whitney Automotive Group, Inc. (referred to herein as “WAG”), at the time, the nation’s leading catalog and internet direct marketer of automotive aftermarket performance parts and accessories. This acquisition has expanded our product line into all terrain vehicles, recreational vehicles and motorcycles, as well as provided us deep product knowledge into niche segments like Jeep, Volkswagen and trucks. The expansion of our product line increases our ability to reach customers in the do-it-yourself (“DIY”) automobile and off-road accessories market. Our flagship websites are located at www.autopartswarehouse.com, www.partstrain.com, www.jcwhitney.com, www.stylintrucks.com and www.AutoMD.com and our corporate website is located at www.usautoparts.net.

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Our Products

We offer a broad selection of aftermarket auto parts. We frequently refine our product offering by introducing new merchandise and updating the existing product selection to offer a more complete and relevant product line and to remove low-selling or obsolete SKUs. We broadly classify our products into three categories: body parts, engine parts, and performance parts and accessories.

Body Parts. The body parts category is primarily comprised of parts for the exterior of an automobile. Our parts in this category are typically replacement parts for original body parts that have been damaged as a result of a collision or through general wear and tear. The majority of these products are sold through our websites. In addition, we sell an extensive line of mirror products, including our own private-label brand called Kool-Vue™, which are marketed and sold as aftermarket replacement parts and as upgrades to existing parts.

Engine/Hard Parts. The engine parts category is comprised of engine components and other mechanical and electrical parts, which are often referred to as hard parts. These parts serve as replacement parts for existing engine parts and are generally used by professionals and do-it-yourselfers for engine and mechanical maintenance and repair.

Performance Parts and Accessories. We offer performance versions of many parts sold in each of the above categories. Performance parts and accessories generally consist of parts that enhance the performance of the automobile, upgrade existing functionality of a specific part or improve the physical appearance or comfort of the automobile.

Our Sales Channels

Our sales channels include the online channel and the offline channel.

Online Sales Channel. Our online sales channel consists of our e-commerce channel, online marketplaces and online advertising. Our e-commerce channel includes a network of e-commerce websites, supported by our call-center sales agents. We also sell our products through online marketplaces, including third-party auction sites and shopping portals, which provide us with access to additional consumer segments. The majority of our online sales are to individual consumers. We sell online advertising and sponsorship positions on our e-commerce websites to highlight vendor brands and offer complementary products and services that benefit our customers. Advertising is targeted to specific sections of the websites and can also be targeted to specific users based on the vehicles they drive. Advertising partners primarily include part vendors, national automotive aftermarket brands, and automobile manufacturers.

Offline Sales Channel. We sell and deliver to collision repair shops throughout Southern California and the state of Virginia via our offline sales channel. We also market our Kool-Vue™ products nationwide to auto parts wholesale distributors and serve consumers by operating retail outlet stores in Independence, Ohio and LaSalle, Illinois.

Our Fulfillment Operations

We fulfill customer orders using two primary methods: (i) stock-and-ship, where we take physical delivery of merchandise and store it in one of our distribution centers until it is shipped to a customer, and (ii) drop-ship, where merchandise is shipped directly to customers from our suppliers. We believe that the flexibility of fulfilling orders using two different fulfillment methods allows us to offer a broader product selection, helps optimize product inventory and enhances our overall business profitability.

The selection of fulfillment methodology occurs at the time of order submission. When a customer submits an order, our fulfillment system performs a check on the ordered item to determine if it is in stock at any of our distribution centers. Fulfillment teams in our distribution centers then process orders for in-stock products. Orders for non-stocked products are sent to our suppliers and processed via drop-ship.

Stock-and-Ship Fulfillment. Our stock-and-ship products are sourced primarily from manufacturers and other suppliers located in Asia and in the U.S. and are stored in one of our distribution centers in Carson, California; Chesapeake, Virginia; LaSalle, Illinois; and Independence, Ohio. All products received into our distribution centers are entered into our inventory management systems, allowing us to closely monitor inventory availability. We consider a number of factors in determining which items to stock in our distribution centers, including which products can be purchased at a meaningful discount to domestic prices for similar items, which products have historically sold in high volumes, and which products may be out of stock when we attempt to fulfill via drop-ship.

Drop-Ship Fulfillment. We have developed relationships with several U.S.-based automobile parts distributors that operate their own distribution centers and will deliver products directly to our customers. We internally developed a proprietary distributor selection system, Auto-Vend™, which allows us to electronically select multiple vendors for a given order. Auto-Vend™ will attempt to first direct an order to one of our warehouses. If the product is not in stock, Auto-Vend™ will process the order to the next appropriate vendor based on customer location, contractual agreements, and service level history.

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Suppliers

We source our products from foreign manufacturers and importers located in Taiwan and China, and from U.S. manufacturers and distributors. We drop-ship orders for low demand products manufactured in the U.S. directly from our manufacturers and distributors. We generally place large-volume orders with these suppliers and, as a result, may receive volume discounts on certain ordered products. Our domestic suppliers offer direct-to-customer shipping, allowing us to save on fulfillment costs and offer a broader selection of products. We have developed application programming interfaces with several of these suppliers that allow us to electronically transmit orders and check inventory availability. We are a significant customer for many of our drop-ship vendors and have long standing relationships and contracts with many of these suppliers. For the fiscal year ended December 31, 2011, two of our drop-ship vendors provided 18.7% of our total product purchases.

Marketing

Our online marketing efforts are designed to attract visitors to our websites, convert visitors into purchasing customers and encourage repeat purchases among our existing customer base. We use a variety of online marketing methods to attract visitors, including paid search advertising, search engine optimization, affiliate programs, e-mail marketing and inclusion in online shopping engines. To convert visitors into paying customers, we periodically run in-site promotions for discounted purchases. We seek to create cross-selling opportunities by displaying complementary and related products available for sale throughout the purchasing process. We utilize several marketing techniques, including targeted e-mails about specific vehicle promotions, to increase customer awareness of our products.

International Operations

In April 2007, we established offshore operations in the Philippines. Our offshore operations allow us to access a workforce with the necessary technical skills at a significantly lower cost than comparably experienced U.S.-based professionals. Our offshore operations are responsible for a majority of our website development, catalog management, and back office support. Our offshore operations also house our main call center. We have 1,005 employees in the Philippines.

In addition to our operations in the Philippines, we have a Canadian subsidiary to facilitate sales of our products in Canada; the subsidiary has no distribution center or employees. We also ship parts directly to Canada and elsewhere throughout the world through a freight forwarding partner. In 2011, we shipped auto parts to over 160 different countries.

Competition

The auto repair information and parts industry is competitive and highly fragmented, with products distributed through multi-tiered and overlapping channels. We compete with both online and offline retailers who offer original equipment manufacturer (“OEM”) and aftermarket parts to either the DIY or do-it-for-me (“DIFM”) customer segments. Current or potential competitors include the following:

We believe the principal competitive factors in our market are helping customers easily find their parts, educating consumers on the service and maintenance of their vehicles, maintaining a proprietary product catalog that maps individual parts to relevant vehicle applications, broad product selection and availability, price, knowledgeable customer service, and rapid order fulfillment and delivery. We believe we compete favorably on the basis of these factors. However, some of our competitors may be larger, have stronger brand recognition or may have access to greater financial, technical and marketing resources or have been operating longer than we have.

Government Regulation

        We are subject to federal and state consumer protection laws, including laws protecting the privacy of customer non-public information and the handling of customer complaints and regulations prohibiting unfair and deceptive trade practices. The growth and demand for online commerce has and may continue to result in more stringent consumer protection laws that impose additional compliance burdens on online companies. These laws may cover issues such as user privacy, spyware and the tracking of consumer activities, marketing e-mails and communications, other advertising and promotional practices, money transfers, pricing, content and quality of products and services, taxation, electronic contracts and other communications and information security. In addition, most states have passed laws that prohibit or limit the use of aftermarket auto parts in collision repair work and/or require enhanced disclosure or vehicle owner consent before using aftermarket auto parts in such repair work and additional legislation of this kind may be introduced in the future.

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There is also great uncertainty over whether or how existing laws governing issues such as property ownership, sales and other taxes, auctions, libel and personal privacy apply to the Internet and commercial online services. These issues may take years to resolve. For example, tax authorities in a number of states, as well as a Congressional advisory commission, are currently reviewing the appropriate tax treatment of companies engaged in online commerce, and new state tax regulations may subject us to additional state sales and income taxes. New legislation or regulation, the application of laws and regulations from jurisdictions whose laws do not currently apply to our business or the application of existing laws and regulations to the Internet and commercial online services could result in significant additional taxes or regulatory restrictions on our business. These taxes or restrictions could have an adverse effect on our cash flows and results of operations. Furthermore, there is a possibility that we may be subject to significant fines or other payments for any past failures to comply with these requirements.

Environmental

We are subject to environmental regulation as it affects certain of the products we sell. For instance, California currently only allows catalytic converters approved by the state to be sold within the state and, during 2010 and early 2011, the Company met with the California Air Resources Board (“CARB”) to discuss alleged sales of catalytic converters into California by the Company and third-party suppliers that are not compliant with California regulations. CARB informed the Company that penalties shall be assessed with regard to any non-compliant sales. On October 26, 2011, the Company and CARB entered into a settlement agreement related to this inquiry. Without admitting any liability, the Company agreed to pay a non-material cash penalty, subject to being offset by contributions from some of the Company’s third-party suppliers, in exchange for a release from CARB of the Company and such third-party suppliers. There has been an indication that other states may be pursuing the enactment of similar regulations. In addition, if we expanded our product lines, we may be subject to additional environmental regulation.

Seasonality

We believe our business is subject to seasonal fluctuations. We have historically experienced higher sales of body parts in winter months when inclement weather and hazardous road conditions typically result in more automobile collisions. Engine parts and performance parts and accessories have historically experienced higher sales in the summer months when consumers have more time to undertake elective projects to maintain and enhance the performance of their automobiles and the warmer weather during that time is conducive for such projects. We expect the historical seasonality trends to continue to have a material impact on our financial condition and results of operations in subsequent periods.

Employees

As of December 31, 2011, we had 516 employees in the United States and 1,005 employees in the Philippines for a total of 1,521 employees. None of our employees are represented by a labor union, and we have never experienced a work stoppage.

Available Information

Our Annual Reports on Form 10-K, Quarterly Reports on Form 10-Q, Current Reports on Form 8-K, and amendments to those reports are available free of charge on the Investor Relations section of our corporate website located at www.usautoparts.net as soon as reasonably practicable after such reports are electronically filed with, or furnished to, the Securities and Exchange Commission (“SEC”). The inclusion of our website address in this report does not include or incorporate by reference into this report any information on our website.

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Our business is subject to a number of risks which are discussed below. Other risks are presented elsewhere in this report and in the information incorporated by reference into this report. You should consider carefully the following risks in addition to the other information contained in this report and our other filings with the SEC, including our subsequent reports on Forms 10-Q and 8-K, and any amendments thereto, before deciding to buy, sell or hold our common stock. If any of these known or unknown risks or uncertainties actually occurs with material adverse effects on us, our business, financial condition, results of operations and/or liquidity could be seriously harmed. In that event, the market price for our common stock will likely decline and you may lose all or part of your investment.

Risks Related To Our Business

Purchasers of aftermarket auto parts may not choose to shop online, which would prevent us from acquiring new customers who are necessary to the growth of our business.

The online market for aftermarket auto parts is less developed than the online market for many other business and consumer products, and currently represents only a small part. Our success will depend in part on our ability to attract new customers and to convert customers who have historically purchased auto parts through traditional retail and wholesale operations. Furthermore, we may have to incur significantly higher and more sustained advertising and marketing expenditures or may need to price our products more competitively than we currently anticipate in order to attract additional online consumers and convert them into purchasing customers. Specific factors that could prevent prospective customers from purchasing from us include:

If the online market for auto parts does not gain widespread acceptance, our sales may decline and our business and financial results may suffer.

We depend on search engines and other online sources to attract visitors to our websites, and if we are unable to attract these visitors and convert them into customers in a cost-effective manner, our business and results of operations will be harmed.

Our success depends on our ability to attract online consumers to our websites and convert them into customers in a cost-effective manner. We are significantly dependent upon search engines, shopping comparison sites and other online sources for our website traffic. We are included in search results as a result of both paid search listings, where we purchase specific search terms that will result in the inclusion of our listing, and algorithmic searches that depend upon the searchable content on our sites. Algorithmic listings cannot be purchased and instead are determined and displayed solely by a set of formulas utilized by the search engine. Search engines, shopping comparison sites and other online sources revise their algorithms from time to time in an attempt to optimize their search results. If one or more of the search engines, shopping comparison sites or other online sources on which we rely for website traffic were to modify its general methodology for how it displays or selects our websites, it could result in fewer consumers clicking through to our websites, and our financial results could be adversely affected. We operate a multiple website platform that generally allows us to provide multiple search results for a particular algorithmic search. If the search engines were to limit our display results to a single result or entirely eliminate our results from the algorithmic search, our website traffic would significantly decrease and our business would be materially harmed. If any free search engine or shopping comparison site on which we rely begins charging fees for listing or placement, or if one or more of the search engines, shopping comparison sites and other online sources on which we rely for purchased listings, modifies or terminates its relationship with us, our expenses could rise, we could lose customers and traffic to our websites could decrease. In addition, our success in attracting visitors who convert to customers will depend in part upon our ability to identify and purchase relevant search terms, provide relevant content on our sites, and effectively target our other marketing programs such as e-mail campaigns and affiliate programs. If we are unable to attract visitors to our websites and convert them to customers in a cost-effective manner, then our sales may decline and our business and financial results may be harmed.

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We may not be able to successfully acquire new businesses or integrate acquisitions, which could cause our business to suffer.

We may not be able to successfully complete potential strategic acquisitions if we cannot reach agreement on acceptable terms or for other reasons. If we buy a company or a division of a company, we may experience difficulty integrating that company’s or division’s personnel and operations, which could negatively affect our operating results. In addition:

As part of our growth strategy, we acquired WAG on August 12, 2010 and we expect that we will selectively pursue additional acquisitions of businesses, technologies or services in order to expand our capabilities, enter new markets or increase our market share. In conjunction with the acquisition of WAG, we recorded a significant valuation allowance against our deferred tax asset, and have incurred greater than usual legal and accounting fees, as well as general and administrative expenses. Additionally, because the acquisition of WAG was a stock purchase, we may incur liability for acts taken prior to our acquisition that may involve costly litigation. Integrating any newly acquired businesses’ websites, technologies or services is likely to be expensive and time consuming. For example, our acquisition of All OEM Parts, Inc., Partsbin.com, Inc., and other affiliated companies (collectively “Partsbin”), resulted in significant costs, including a material impairment charge, a write-down of goodwill associated with the acquisition, and a number of challenges, including retaining employees of the acquired company, integrating our order processing and credit processing, integrating our product pricing strategy, and integrating the diverse technologies and differing e-commerce platforms and accounting systems used by each company. Our integration activities in connection with our acquisitions have also caused a substantial diversion of our management’s attention. If we are unable to successfully complete the integration of acquisitions, we may not realize the anticipated synergies from such acquisitions, we may take impairment charges and write-downs associated with such acquisitions, and our business and results of operations could suffer. In connection with the acquisition of WAG, during fiscal 2011, we incurred acquisition and integration related costs of $7.4 million and recorded a non-cash impairment charge on certain trade name intangible assets totaling $5.1 million (see “Note 6- Goodwill and Intangibles” of the Notes to Consolidated Financial Statements included in Part IV, Item 15 of this report).

Our operations are restricted by our credit facility.

Our credit facility includes a number of restrictive covenants. These covenants could impair our financing and operational flexibility and make it difficult for us to react to market conditions and satisfy our ongoing capital needs and unanticipated cash requirements. Specifically, such covenants restrict our ability and, if applicable, the ability of our subsidiaries to, among other things:

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In addition, our current credit facility requires us to satisfy certain financial covenants. These financial covenants and tests could limit our ability to react to market conditions or satisfy extraordinary capital needs and could otherwise restrict our financing and operations.

Our ability to comply with the covenants and other terms of our debt obligations will depend on our future operating performance. If we fail to comply with such covenants and terms, we would be required to obtain waivers from our lenders to maintain compliance with our debt obligations. As of January 1, 2011 and October 1, 2011, in connection with our credit facility, our consolidated fixed charge coverage ratio was lower than the ratio required by the covenants in the credit facility. In February 2011 and October 2011, we and Silicon Valley Bank (“Bank”) entered into Amendment No. 1 and Amendment No. 2, respectively, to Loan and Security Agreement and Limited Waiver (collectively, the “Amendments”). The Amendments waived our lack of compliance with the consolidated fixed charge coverage ratio covenant in the loan agreement as of January 1, 2011 and October1, 2011. The Amendments also amended the definition of “Consolidated EBITDA” (Earnings Before Interest, Taxes, Depreciation and Amortization) to more readily accommodate our integration of the WAG acquisition. In December 2011, the Company and the Bank entered into Amendment No. 3 to Loan and Security Agreement in connection with a vendor purchasing card program with J.P Morgan Chase Bank, N.A. During March 2012, the Company determined it was probable that the consolidated fixed charge coverage ratio would not be in compliance with the required minimum level for the quarter ending March 31, 2012. This determination was made during the Company’s monitoring of their covenants, which includes monthly calculations of “Consolidated EBITDA” projected to quarter end. As a result, on March 23, 2012, the Company and the Bank entered into Amendment No. 4 to Loan and Security Agreement (the “Fourth Amendment”). The Fourth Amendment reduced the required consolidated fixed charge coverage ratio to a level we are projected to be in compliance with as of March 31, 2012. In the future, if we are unable to obtain any necessary waivers and the debt is accelerated, a material adverse effect on our financial condition and future operating performance would result. Additionally, our indebtedness could have important consequences, including the following:

Furthermore, our ability to satisfy our debt service obligations will depend, among other things, upon fluctuations in interest rates, our future operating performance and ability to refinance indebtedness when and if necessary. These factors depend partly on economic, financial, competitive and other factors beyond our control. We may not be able to generate sufficient cash from operations to meet our debt service obligations as well as fund necessary capital expenditures and general operating expenses. In addition, if we need to refinance our debt, or obtain additional financing or sell assets or equity to satisfy our debt service obligations, we may not be able to do so on commercially reasonable terms, if at all.

If we are unable to manage the challenges associated with our international operations, the growth of our business could be limited and our business could suffer.

We maintain international business operations in the Philippines. This international operation includes development and maintenance of our websites, Internet marketing personnel, and sales and customer support services. We also operate a Canadian subsidiary to facilitate sales in Canada. We are subject to a number of risks and challenges that specifically relate to our international operations. Our international operations may not be successful if we are unable to meet and overcome these challenges, which could limit the growth of our business and may have an adverse effect on our business and operating results. These risks and challenges include:

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We are dependent upon relationships with suppliers in Taiwan, China and the United States for the vast majority of our products.

We acquire substantially all of our products from manufacturers and distributors located in Taiwan, China and the United States. Our top ten suppliers represented approximately 41% of our total product purchases during the fifty-two weeks ended December 31, 2011 (“fiscal 2011”). We do not have any long-term contracts or exclusive agreements with our foreign suppliers that would ensure our ability to acquire the types and quantities of products we desire at acceptable prices and in a timely manner. In addition, our ability to acquire products from our suppliers in amounts and on terms acceptable to us is dependent upon a number of factors that could affect our suppliers and which are beyond our control. For example, financial or operational difficulties that some of our suppliers may face could result in an increase in the cost of the products we purchase from them. In addition, the increasing consolidation among auto parts suppliers may disrupt or end our relationship with some suppliers, result in product shortages and/or lead to less competition and, consequently, higher prices.

In addition, because many of our suppliers are outside of the United States, additional factors could interrupt our relationships or affect our ability to acquire the necessary products on acceptable terms, including:

If we do not maintain our relationships with our existing suppliers or develop relationships with new suppliers on acceptable commercial terms, we may not be able to continue to offer a broad selection of merchandise at competitive prices and, as a result, we could lose customers and our sales could decline.

We are dependent upon third parties for distribution and fulfillment operations with respect to many of our products.

For a number of the products that we sell, we outsource the distribution and fulfillment operation and are dependent on our distributors to manage inventory, process orders and distribute those products to our customers in a timely manner. For fiscal 2011, our product purchases from two drop-ship suppliers represented 18.7% of our total product purchases. If we do not maintain our existing relationships with these suppliers and our other distributors on acceptable commercial terms, we will need to obtain other suppliers and may not be able to continue to offer a broad selection of merchandise at competitive prices, and our sales may decrease.

In addition, because we outsource to distributors a number of these traditional retail functions relating to those products, we have limited control over how and when orders are fulfilled. We also have limited control over the products that our distributors purchase or keep in stock. Our distributors may not accurately forecast the products that will be in high demand or they may allocate popular products to other resellers, resulting in the unavailability of certain products for delivery to our customers. Any inability to offer a broad array of products at competitive prices and any failure to deliver those products to our customers in a timely and accurate manner may damage our reputation and brand and could cause us to lose customers.

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We depend on third-party delivery services to deliver our products to our customers on a timely and consistent basis, and any deterioration in our relationship with any one of these third parties or increases in the fees that they charge could harm our reputation and adversely affect our business and financial condition.

We rely on third parties for the shipment of our products and we cannot be sure that these relationships will continue on terms favorable to us, or at all. Shipping costs have increased from time to time, and may continue to increase, which could harm our business, prospects, financial condition and results of operations by increasing our costs of doing business and resulting in reduced gross margins. In addition, if our relationships with these third parties are terminated or impaired, or if these third parties are unable to deliver products for us, whether due to labor shortage, slow down or stoppage, deteriorating financial or business condition, responses to terrorist attacks or for any other reason, we would be required to use alternative carriers for the shipment of products to our customers. Changing carriers could have a negative effect on our business and operating results due to reduced visibility of order status and package tracking and delays in order processing and product delivery, and we may be unable to engage alternative carriers on a timely basis, upon terms favorable to us, or at all.

If commodity prices such as fuel, plastic and steel continue to increase, our margins may shrink.

Our third party delivery services have increased fuel surcharges from time to time, and such increases negatively impact our margins, as we are generally unable to pass all of these costs directly to consumers. Increasing prices in the component materials for the parts we sell may impact the availability, the quality and the price of our products, as suppliers search for alternatives to existing materials and as they increase the prices they charge. We cannot ensure that we can recover all the increased costs through price increases, and our suppliers may not continue to provide the consistent quality of product as they may substitute lower cost materials to maintain pricing levels, all of which may have a negative impact on our business and results of operations.

If our fulfillment operations are interrupted for any significant period of time or are not sufficient to accommodate increased demand, our sales would decline and our reputation could be harmed.

Our success depends on our ability to successfully receive and fulfill orders and to promptly deliver our products to our customers. The majority of orders for our auto body parts products are filled from our inventory in our distribution centers, where all our inventory management, packaging, labeling and product return processes are performed. Increased demand and other considerations may require us to expand our distribution centers or transfer our fulfillment operations to larger facilities in the future.

Our distribution centers are susceptible to damage or interruption from human error, fire, flood, power loss, telecommunications failures, terrorist attacks, acts of war, break-ins, earthquakes and similar events. We do not currently maintain back-up power systems at our fulfillment centers. We do not presently have a formal disaster recovery plan and our business interruption insurance may be insufficient to compensate us for losses that may occur in the event operations at our fulfillment center are interrupted. Any interruptions in our fulfillment operations for any significant period of time, including interruptions resulting from the expansion of our existing facilities or the transfer of operations to a new facility, could damage our reputation and brand and substantially harm our business and results of operations and alternate arrangements may increase the cost of fulfillment. In addition, if we do not successfully expand our fulfillment capabilities in response to increases in demand, we may not be able to substantially increase our net sales.

We rely on bandwidth and data center providers and other third parties to provide products to our customers, and any failure or interruption in the services provided by these third parties could disrupt our business and cause us to lose customers.

We rely on third-party vendors, including data center and bandwidth providers. Any disruption in the network access or co-location services, which are the services that house and provide Internet access to our servers, provided by these third-party providers or any failure of these third-party providers to handle current or higher volumes of use could significantly harm our business. Any financial or other difficulties our providers face may have negative effects on our business, the nature and extent of which we cannot predict. We exercise little control over these third-party vendors, which increases our vulnerability to problems with the services they provide. We also license technology and related databases from third parties to facilitate elements of our e-commerce platform. We have experienced and expect to continue to experience interruptions and delays in service and availability for these elements. Any errors, failures, interruptions or delays experienced in connection with these third-party technologies could negatively impact our relationship with our customers and adversely affect our business.

Our systems also heavily depend on the availability of electricity, which also comes from third-party providers. If we were to experience a major power outage, we would have to rely on back-up generators. These back-up generators may not operate properly through a major power outage, and their fuel supply could also be inadequate during a major power outage. Information systems such as ours may be disrupted by even brief power outages, or by the fluctuations in power resulting from switches to and from backup generators. This could disrupt our business and cause us to lose customers.

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We face intense competition and operate in an industry with limited barriers to entry, and some of our competitors may have greater resources than us and may be better positioned to capitalize on the growing e-commerce auto parts market.

The auto parts industry is competitive and highly fragmented, with products distributed through multi-tiered and overlapping channels. We compete with both online and offline retailers who offer OEM and aftermarket auto parts to either the DIY or DIFM customer segments. Current or potential competitors include the following:

Barriers to entry are low, and current and new competitors can launch websites at a relatively low cost. Many of our current and potential offline competitors have longer operating histories, larger customer bases, greater brand recognition and significantly greater financial, marketing, technical, management and other resources than we do. In addition, some of our competitors have used and may continue to use aggressive pricing tactics and devote substantially more financial resources to website and system development than we do. We expect that competition will further intensify in the future as Internet use and online commerce continue to grow worldwide. Increased competition may result in reduced sales, lower operating margins, reduced profitability, loss of market share and diminished brand recognition.

We would also experience significant competitive pressure if any of our suppliers were to sell their products directly to customers. Since our suppliers have access to merchandise at very low costs, they could sell products at lower prices and maintain higher gross margins on their product sales than we can. In this event, our current and potential customers may decide to purchase directly from these suppliers. Increased competition from any supplier capable of maintaining high sales volumes and acquiring products at lower prices than us could significantly reduce our market share and adversely impact our financial results.

If we fail to offer a broad selection of products at competitive prices to meet our customers’ demands, our revenue could decline.

In order to expand our business, we must successfully offer, on a continuous basis, a broad selection of auto parts that meet the needs of our customers. Our auto parts are used by consumers for a variety of purposes, including repair, performance, improved aesthetics and functionality. In addition, to be successful, our product offerings must be broad and deep in scope, competitively priced, well-made, innovative and attractive to a wide range of consumers. We cannot predict with certainty that we will be successful in offering products that meet all of these requirements. If our product offerings fail to satisfy our customers’ requirements or respond to changes in customer preferences, our revenue could decline.

Challenges by OEMs to the validity of the aftermarket auto parts industry and claims of intellectual property infringement could adversely affect our business and the viability of the aftermarket auto parts industry.

OEMs have attempted to use claims of intellectual property infringement against manufacturers and distributors of aftermarket products to restrict or eliminate the sale of aftermarket products that are the subject of the claims. The OEMs have brought such claims in federal court and with the United States International Trade Commission. We have received in the past, and we anticipate we may in the future receive, communications alleging that certain products we sell infringe the patents, copyrights, trademarks and trade names or other intellectual property rights of OEMs or other third parties. For instance, after approximately three and a half years of litigation and related costs and expenses, on April 16, 2009, we entered into a settlement agreement with Ford Motor Company and Ford Global Technologies, LLC that ended the two legal actions that were initiated by Ford against us related to claims of intellectual property infringement.

The United States Patent and Trademark Office records indicate that OEMs are seeking and obtaining more design patents then they have in the past. To the extent that the OEMs are successful with intellectual property infringement claims, we could be restricted or prohibited from selling certain aftermarket products which could have an adverse effect on our business. Infringement claims could also result in increased costs of doing business arising from increased legal expenses, adverse judgments or settlements or changes to our business practices required to settle such claims or satisfy any judgments. Litigation could result in interpretations of the law that require us to change our business practices or otherwise increase our costs and harm our business. We do not maintain insurance coverage to cover the types of claims that could be asserted. If a successful claim were brought against us, it could expose us to significant liability.

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If we are unable to protect our intellectual property rights, our reputation and brand could be impaired and we could lose customers.

We regard our trademarks, trade secrets and similar intellectual property such as our proprietary back-end order processing and fulfillment code and process as important to our success. We rely on trademark and copyright law, and trade secret protection, and confidentiality and/or license agreements with employees, customers, partners and others to protect our proprietary rights. We cannot be certain that we have taken adequate steps to protect our proprietary rights, especially in countries where the laws may not protect our rights as fully as in the United States. In addition, our proprietary rights may be infringed or misappropriated, and we could be required to incur significant expenses to preserve them. For instance, on June 25, 2009, we filed a lawsuit in United States District Court, Central District of California against PartsGeek LLC, its members and several of its employees, alleging, among other things, misappropriation of trade secrets, breach of contract and unfair competition. We are requesting both monetary and injunctive relief. The outcome of such litigation is uncertain, and the cost of prosecuting the litigation may have an adverse impact on our earnings. We have common law trademarks, as well as pending federal trademark registrations for several marks and several registered marks. Even if we obtain approval of such pending registrations, the resulting registrations may not adequately cover our intellectual property or protect us against infringement by others. Effective trademark, service mark, copyright, patent and trade secret protection may not be available in every country in which our products and services may be made available online. We also currently own or control a number of Internet domain names, including www.usautoparts.net, www.autopartswarehouse.com, www.partstrain.com, www.jcwhitney.com, www.AutoMD.com and www.stylintrucks.com, and have invested time and money in the purchase of domain names and other intellectual property, which may be impaired if we cannot protect such intellectual property. We may be unable to protect these domain names or acquire or maintain relevant domain names in the United States and in other countries. If we are not able to protect our trademarks, domain names or other intellectual property, we may experience difficulties in achieving and maintaining brand recognition and customer loyalty.

If our product catalog database is stolen, misappropriated or damaged, or if a competitor is able to create a substantially similar catalog without infringing our rights, then we may lose an important competitive advantage.

We have invested significant resources and time to build and maintain our product catalog, which is maintained in the form of an electronic database, which maps SKUs to relevant product applications based on vehicle makes, models and years. We believe that our product catalog provides us with an important competitive advantage in both driving traffic to our websites and converting that traffic to revenue by enabling customers to quickly locate the products they require. We cannot assure you that we will be able to protect our product catalog from unauthorized copying or theft or that our product catalog will continue to operate adequately, without any technological challenges. In addition, it is possible that a competitor could develop a catalog or database that is similar to or more comprehensive than ours, without infringing our rights. In the event our product catalog is damaged or is stolen, copied or otherwise replicated to compete with us, whether lawfully or not, we may lose an important competitive advantage and our business could be harmed.

Our e-commerce system is dependent on open-source software, which exposes us to uncertainty and potential liability.

We utilize open-source software such as Linux, Apache, MySQL, PHP, Fedora and Perl throughout our web properties and supporting infrastructure although we have created proprietary programs. Open-source software is maintained and upgraded by a general community of software developers under various open-source licenses, including the GNU General Public License (“GPL”). These developers are under no obligation to maintain, enhance or provide any fixes or updates to this software in the future. Additionally, under the terms of the GPL and other open-source licenses, we may be forced to release to the public source-code internally developed by us pursuant to such licenses. Furthermore, if any of these developers contribute any code of others to any of the software that we use, we may be exposed to claims and liability for intellectual property infringement. A number of lawsuits are currently pending against third parties over the ownership rights to the various components within some open-source software that we use. If the outcome of these lawsuits is unfavorable, we may be held liable for intellectual property infringement based on our use of these open-source software components. We may also be forced to implement changes to the code-base for this software or replace this software with internally developed or commercially licensed software.

We face exposure to product liability lawsuits.

The automotive industry in general has been subject to a large number of product liability claims due to the nature of personal injuries that result from car accidents or malfunctions. As a distributor of auto parts, including parts obtained overseas, we could be held liable for the injury or damage caused if the products we sell are defective or malfunction. While we carry insurance against product liability claims, if the damages in any given action were high or we were subject to multiple lawsuits, the damages and costs could exceed the limits of our insurance coverage. If we were required to pay substantial damages as a result of these lawsuits, it may seriously harm our business and financial condition. Even defending against unsuccessful claims could cause us to incur significant expenses and result in a diversion of management’s attention. In addition, even if the money damages themselves did not cause substantial harm to our business, the damage to our reputation and the brands offered on our websites could adversely affect our future reputation and our brand, and could result in a decline in our net sales and profitability.

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We rely on key personnel and may need additional personnel for the success and growth of our business.

Our business is largely dependent on the personal efforts and abilities of highly skilled executive, technical, managerial, merchandising, marketing, and call center personnel. Competition for such personnel is intense, and we cannot assure you that we will be successful in attracting and retaining such personnel. The loss of any key employee or our inability to attract or retain other qualified employees could harm our business and results of operations.

System failures, including failures due to natural disasters or other catastrophic events, could prevent access to our websites, which could reduce our net sales and harm our reputation.

Our sales would decline and we could lose existing or potential customers if they are not able to access our websites or if our websites, transactions processing systems or network infrastructure do not perform to our customers’ satisfaction. Any Internet network interruptions or problems with our websites could:

We have experienced brief computer system interruptions in the past, and we believe they will continue to occur from time to time in the future. Our systems and operations are also vulnerable to damage or interruption from a number of sources, including a natural disaster or other catastrophic event such as an earthquake, typhoon, volcanic eruption, fire, flood, terrorist attack, computer viruses, power loss, telecommunications failure, physical and electronic break-ins and other similar events. For example, our headquarters and the majority of our infrastructure, including some of our servers, are located in Southern California, a seismically active region. We also maintain offshore and outsourced operations in the Philippines, an area that has been subjected to a typhoon and a volcanic eruption in the past. In addition, California has in the past experienced power outages as a result of limited electrical power supplies and due to recent fires in the southern part of the state. Such outages, natural disasters and similar events may recur in the future and could disrupt the operation of our business. Our technology infrastructure is also vulnerable to computer viruses, physical or electronic break-ins and similar disruptions. Although the critical portions of our systems are redundant and backup copies are maintained offsite, not all of our systems and data are fully redundant. We do not presently have a formal disaster recovery plan in effect and may not have sufficient insurance for losses that may occur from natural disasters or catastrophic events. Any substantial disruption of our technology infrastructure could cause interruptions or delays in our business and loss of data or render us unable to accept and fulfill customer orders or operate our websites in a timely manner, or at all.

Risks Related To Our Common Stock

Our stock price has been and may continue to be volatile, which may result in losses to our stockholders.

The market prices of technology and e-commerce companies generally have been extremely volatile and have recently experienced sharp share price and trading volume changes. The trading price of our common stock is likely to be volatile and could fluctuate widely in response to, among other things, the risk factors described in this report and other factors beyond our control such as fluctuations in the operations or valuations of companies perceived by investors to be comparable to us, our ability to meet analysts’ expectations, or conditions or trends in the Internet or auto parts industries.

Since the completion of our initial public offering in February 2007, the trading price of our common stock has been volatile, ranging from a high of $12.61 per share to a low per share of $1.00. We have also experienced significant fluctuations in the trading volume of our common stock. General economic and political conditions unrelated to our performance may also adversely affect the price of our common stock. In the past, following periods of volatility in the market price of a public company’s securities, securities class action litigation has often been initiated. Due to the inherent uncertainties of litigation, we cannot predict the ultimate outcome of any such litigation if it were initiated. The initiation of any such litigation or an unfavorable result could have a material adverse effect on our financial condition and results of operation.

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Our executive officers and directors own a significant percentage of our stock.

As of December 31, 2011, our executive officers and directors and entities that are affiliated with them beneficially owned in the aggregate approximately 46.1% of our outstanding shares of common stock. This significant concentration of share ownership may adversely affect the trading price for our common stock because investors often perceive disadvantages in owning stock in companies with controlling stockholders. Also, these stockholders, acting together, will be able to significantly influence our management and affairs and matters requiring stockholder approval including the election of our entire Board of Directors and certain significant corporate actions such as mergers, consolidations or the sale of substantially all of our assets. As a result, this concentration of ownership could delay, defer or prevent others from initiating a potential merger, takeover or other change in our control, even if these actions would benefit our other stockholders and us.

Our future operating results may fluctuate and may fail to meet market expectations.

We expect that our revenue and operating results will continue to fluctuate from quarter to quarter due to various factors, many of which are beyond our control. If our quarterly revenue or operating results fall below the expectations of investors or securities analysts, the price of our common stock could significantly decline. The factors that could cause our operating results to continue to fluctuate include, but are not limited to:

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If we fail to maintain an effective system of internal control over financial reporting or comply with Section 404 of the Sarbanes-Oxley Act of 2002, we may not be able to accurately report our financial results or prevent fraud, and our stock price could decline.

While management has concluded that our internal controls over financial reporting were effective as of December 31, 2011, we have in the past, and could in the future, have a material weakness or significant deficiency in our control over financial reporting or fail to comply with Section 404 of the Sarbanes-Oxley Act of 2002. If we fail to properly maintain an effective system of internal control over financial reporting, it could impact our ability to prevent fraud or to issue our financial statements in a timely manner that presents fairly our financial condition and results of operations. The existence of any such deficiencies or weaknesses, even if cured, may also lead to the loss of investor confidence in the reliability of our financial statements, could harm our business and negatively impact the trading price of our common stock. Such deficiencies or material weaknesses may also subject us to lawsuits, investigations and other penalties.

Our charter documents could deter a takeover effort, which could inhibit your ability to receive an acquisition premium for your shares.

Provisions in our certificate of incorporation and bylaws could make it more difficult for a third party to acquire us, even if doing so would be beneficial to our stockholders. Such provisions include the following:

We do not intend to pay dividends on our common stock.

We currently intend to retain any future earnings and do not expect to pay any cash dividends on our capital stock for the foreseeable future.

General Market and Industry Risk

Economic conditions have had, and may continue to have an adverse effect on the demand for aftermarket auto parts and could adversely affect our sales and operating results.

We sell aftermarket auto parts consisting of body and engine parts used for repair and maintenance, performance parts used to enhance performance or improve aesthetics and accessories that increase functionality or enhance a vehicle’s features. Demand for our products has been and may continue to be adversely affected by general economic conditions. In declining economies, consumers often defer regular vehicle maintenance and may forego purchases of nonessential performance and accessories products, which can result in a decrease in demand for auto parts in general. Consumers also defer purchases of new vehicles, which immediately impacts performance parts and accessories, which are generally purchased in the first six months of a vehicle’s lifespan. In addition, during economic downturns some competitors may become more aggressive in their pricing practices, which would adversely impact our gross margin and could cause large fluctuations in our stock price. Certain suppliers may exit the industry which may impact our ability to procure parts and may adversely impact gross margin as the remaining suppliers increase prices to take advantage of limited competition.

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Vehicle miles driven, vehicle accident rates and insurance companies’ willingness to accept a variety of types of replacement parts in the repair process have fluctuated and may decrease, which could result in a decline of our revenues and negatively affect our results of operations.

We and our industry depend on the number of vehicle miles driven, vehicle accident rates and insurance companies’ willingness to accept a variety of types of replacement parts in the repair process. Decreased miles driven reduce the number of accidents and corresponding demand for crash parts, and reduce the wear and tear on vehicles with a corresponding reduction in demand for vehicle repairs and replacement or hard parts, all of which may reduce our revenues and adversely impact our results of operations.

The success of our business depends on the continued growth of the Internet as a retail marketplace and the related expansion of the Internet infrastructure.

Our future success depends upon the continued and widespread acceptance and adoption of the Internet as a vehicle to purchase products. If customers or manufacturers are unwilling to use the Internet to conduct business and exchange information, our business will fail. The commercial acceptance and use of the Internet may not continue to develop at historical rates, or may not develop as quickly as we expect. The growth of the Internet, and in turn the growth of our business, may be inhibited by concerns over privacy and security, including concerns regarding “viruses” and “worms,” reliability issues arising from outages or damage to Internet infrastructure, delays in development or adoption of new standards and protocols to handle the demands of increased Internet activity, decreased accessibility, increased government regulation, and taxation of Internet activity. In addition, our business growth may be adversely affected if the Internet infrastructure does not keep pace with the growing Internet activity and is unable to support the demands placed upon it, or if there is any delay in the development of enabling technologies and performance improvements.

Negative conditions in the global credit markets may impair the liquidity of a portion of our investments portfolio, and adversely affect our results of operations and access to financing.

Our investment securities consist of high-grade auction rate preferred securities (“ARPS”). As of December 31, 2011, our long-term marketable securities were comprised of $2.1 million (fair value) of high-grade (AAA rated) ARPS issued primarily by closed end funds that primarily hold debt obligations from municipalities. The recent negative conditions in the global credit markets have prevented some investors from liquidating their holdings, including their holdings of ARPS.

In response to the credit situation, in February 2008, we instructed our investment advisor to liquidate all our investments in closed end funds and move these funds into money market investments, but there was insufficient demand at auction for our remaining four high-grade ARPS, representing approximately $7.8 million (par value) at that time. As a result, our remaining ARPS currently are not liquid, and have been reclassified as long-term investments. For the period June 30, 2008 through December 31, 2011, approximately $5.7 million of our investments in ARPS were redeemed at par value, but we do not know when we will have access to the capital in our remaining $2.1 million (par value) of ARPS investments. In the event we need to access the funds that are in an illiquid state, we will not be able to do so without a loss of principal or until a future auction on these investments is successful, the securities are redeemed by the issuer or a secondary market emerges. If we cannot readily access these funds, we may be required to borrow funds or issue additional debt or equity securities to meet our capital requirements.

As of December 31, 2011, management concluded that these remaining investments were temporarily impaired and has recognized an unrealized loss in other comprehensive income totaling $21,000. Management is not sure that these investments will not be settled in the short term, although the market for these investments is presently uncertain. If the credit ratings of the security issuers deteriorate and any decline in market value is determined to be other-than-temporary, we would be required to adjust the carrying value of the investment through an additional impairment charge.

We may be subject to liability for sales and other taxes and penalties, which could have an adverse effect on our business.

We currently collect sales or other similar taxes only on the shipment of goods to the states of California, Kansas, Virginia, Illinois and Ohio. The U.S. Supreme Court has ruled that vendors whose only connection with customers in a state is by common carrier or the U.S. mail are free from state-imposed duties to collect sales and use taxes in that state. However, states could seek to impose additional income tax obligations or sales tax collection obligations on out-of-state companies such as ours, which engage in or facilitate online commerce, based on their interpretation of existing laws, including the Supreme Court ruling, or specific facts relating to us. If sales tax obligations are successfully imposed upon us by a state or other jurisdiction, we could be exposed to substantial tax liabilities for past sales and penalties and fines for failure to collect sales taxes. We could also suffer decreased sales in that state or jurisdiction as the effective cost of purchasing goods from us increases for those residing in that state or jurisdiction.

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In addition, a number of states, as well as the U.S. Congress, have been considering various initiatives that could limit or supersede the Supreme Court’s apparent position regarding sales and use taxes on Internet sales. If any of these initiatives are enacted, we could be required to collect sales and use taxes in additional states and our revenue could be adversely affected. Furthermore, the U.S. Congress has not yet extended a moratorium, which was first imposed in 1998 but has since expired, on state and local governments’ ability to impose new taxes on Internet access and Internet transactions. The imposition by state and local governments of various taxes upon Internet commerce could create administrative burdens for us as well as substantially impair the growth of e-commerce and adversely affect our revenue and profitability. Since our service is available over the Internet in multiple states, these jurisdictions may require us to qualify to do business in these states. If we fail to qualify in a jurisdiction that requires us to do so, we could face liabilities for taxes and penalties.

Security threats to our IT infrastructure could expose us to liability, and damage our reputation and business

It is essential to our business strategy that our technology and network infrastructure remain secure and is perceived by our customers to be secure. Despite security measures, however, any network infrastructure may be vulnerable to cyber-attacks by hackers and other security threats. As a leading online source for automotive aftermarket parts and repair information, we may face cyber-attacks that attempt to penetrate our network security, including our data centers, to sabotage or otherwise disable our network of websites and online marketplaces, misappropriate our or our customers’ proprietary information, which may include personally identifiable information, or cause interruptions of our internal systems and services. If successful, any of these attacks could negatively affect our reputation, damage our network infrastructure and our ability to sell our products, harm our relationship with customers that are affected and expose us to financial liability.

If we do not respond to technological change, our websites could become obsolete and our financial results and conditions could be adversely affected.

We maintain a network of websites which requires substantial development and maintenance efforts, and entails significant technical and business risks. To remain competitive, we must continue to enhance and improve the responsiveness, functionality and features of our websites. The Internet and the e-commerce industry are characterized by rapid technological change, the emergence of new industry standards and practices and changes in customer requirements and preferences. Therefore, we may be required to license emerging technologies, enhance our existing websites, develop new services and technology that address the increasingly sophisticated and varied needs of our current and prospective customers, and adapt to technological advances and emerging industry and regulatory standards and practices in a cost-effective and timely manner. Our ability to remain technologically competitive may require substantial expenditures and lead time and our failure to do so may harm our business and results of operations.

Existing or future government regulation could expose us to liabilities and costly changes in our business operations and could reduce customer demand for our products and services.

We are subject to federal and state consumer protection laws and regulations, including laws protecting the privacy of customer non-public information and regulations prohibiting unfair and deceptive trade practices, as well as laws and regulations governing businesses in general and the Internet and e-commerce and certain environmental laws. Additional laws and regulations may be adopted with respect to the Internet, the effect of which on e-commerce is uncertain. These laws may cover issues such as user privacy, spyware and the tracking of consumer activities, marketing e-mails and communications, other advertising and promotional practices, money transfers, pricing, content and quality of products and services, taxation, electronic contracts and other communications, intellectual property rights, and information security. Furthermore, it is not clear how existing laws such as those governing issues such as property ownership, sales and other taxes, trespass, data mining and collection, and personal privacy apply to the Internet and e-commerce. For example, California has enacted legislation banning the sale of catalytic converters that do not meet California emissions regulations, and the current federal administration has indicated that 13 additional states will be allowed to enact their own legislation that mirrors the California legislation. During 2010 and in early 2011, we met with CARB to discuss alleged sales of catalytic converters into California by us and our third-party suppliers that are not compliant with California regulations. CARB informed us that penalties may be assessed with regard to any non-compliant sales and, on October 26, 2011, we and CARB entered into a settlement agreement related this inquiry. Without admitting any liability, we agreed to pay a non-material cash penalty, which was partially offset by contributions from some of our third-party suppliers, in exchange for a release from CARB of us and such third-party suppliers. To the extent we expand into international markets, we will be faced with complying with local laws and regulations, some of which may be materially different than U.S. laws and regulations. Any such foreign law or regulation, any new U.S. law or regulation, or the interpretation or application of existing laws and regulations to the Internet or other online services or our business in general, may have a material adverse effect on our business, prospects, financial condition and results of operations by, among other things, impeding the growth of the Internet, subjecting us to fines, penalties, damages or other liabilities, requiring costly changes in our business operations and practices, and reducing customer demand for our products and services. We do not maintain insurance coverage to cover the types of claims or liabilities that could arise as a result of such regulation.

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We may be affected by global climate change or by legal, regulatory, or market responses to such change.

The growing political and scientific sentiment is that global weather patterns are being influenced by increased levels of greenhouse gases in the earth’s atmosphere. This growing sentiment and the concern over climate change have led to legislative and regulatory initiatives aimed at reducing greenhouse gas emissions. For example, proposals that would impose mandatory requirements on greenhouse gas emissions continue to be considered by policy makers in the United States. Laws enacted that directly or indirectly affect our suppliers (through an increase in the cost of production or their ability to produce satisfactory products) or our business (through an impact on our inventory availability, cost of sales, operations or demand for the products we sell) could adversely affect our business, financial condition, results of operations and cash flows. Significant increases in fuel economy requirements or new federal or state restrictions on emissions of carbon dioxide that may be imposed on vehicles and automobile fuels could adversely affect demand for vehicles, annual miles driven or the products we sell or lead to changes in automotive technology. Compliance with any new or more stringent laws or regulations, or stricter interpretations of existing laws, could require additional expenditures by us or our suppliers. Our inability to respond to changes in automotive technology could adversely impact the demand for our products and our business, financial condition, results of operations or cash flows.

The United States government may substantially increase border controls and impose restrictions on cross-border commerce that may substantially harm our business.

We purchase a substantial portion of our products from foreign manufacturers and other suppliers who source products internationally. Restrictions on shipping goods into the United States from other countries pose a substantial risk to our business. Particularly since the terrorist attacks on September 11, 2001, the United States government has substantially increased border surveillance and controls. If the United States were to impose further border controls and restrictions, impose quotas, tariffs or import duties, increase the documentation requirements applicable to cross border shipments or take other actions that have the effect of restricting the flow of goods from other countries to the United States, we may have greater difficulty acquiring our inventory in a timely manner, experience shipping delays, or incur increased costs and expenses, all of which would substantially harm our business and results of operations.

None.

As of December 31, 2011, the square footage of our leased and owned office and warehouse space was 485,000 and 347,000, respectively. Our corporate headquarters and primary distribution centers are located in Carson, California and LaSalle, Illinois in approximately 510,000 square feet of office and warehouse space. We have a 217,000 square foot distribution center in Chesapeake, Virginia, and an additional 61,000 square foot of warehouse space in Independence, Ohio. We currently lease approximately 43,000 square feet of office space in the Philippines for our employees located in that country.

In September 2011, we entered into a sublease agreement for the leasing of approximately 25,000 square feet of commercial office space located in Carson, California. The sublease will enable us to consolidate our corporate office space from three buildings into one, and will allow us to consolidate our California fulfillment operations into one warehouse, which will reduce our monthly rent expense and potentially create warehouse operating efficiencies once the space consolidation has been completed. For additional information regarding our obligations under property leases, see “Note 12-Commitments and Contingencies” of the Notes to Consolidated Financial Statements, included in Part IV, Item 15 of this report.

The information set forth under the caption “Legal Matters” in Note 12 of the Notes to Consolidated Financial Statements, included in Part IV, Item 15 of this report, is incorporated herein by reference. For an additional discussion of certain risks associated with legal proceedings, see the section entitled “Risk Factors” in Item 1A of this report.

Not applicable.

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PART II

Market Information

Our common stock is being trading on the NASDAQ Global Market under the symbol “PRTS.” The table below sets forth the high and low sales prices of our common stock for the periods indicated:

On March 19, 2012, the last reported sale price of our common stock on the NASDAQ Global Market was $3.60 per share.

Holders

As of March 19, 2012, there were approximately 1,702 holders of record of our common stock.

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Stock Performance Graph

The material in this section is not “soliciting material,” is not deemed “filed” with the SEC, and shall not be deemed to be incorporated by reference into any of our filings under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended.

The following graph shows an annual comparison of the total cumulative returns of an investment of $100 in cash on February 9, 2007, the first trading day following our initial public offering in (i) our common stock, (ii) the Morgan Stanley Technology Index, (iii) the S&P 500 Retail Index and (iv) NASDAQ Composite Index, in each case through December 31, 2011. The comparisons in the graph are required by the SEC and are not intended to forecast or be indicative of the possible future performance of our common stock. The graph assumes that all dividends have been reinvested (to date, we have not declared dividends).

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Dividend Policy

No dividends were paid during the fifty-two week periods ended January 1, 2011 and December 31, 2011. We currently intend to retain any future earnings to finance the growth and development of our business, and we do not anticipate that we will declare or pay any cash dividends on our common stock in the foreseeable future. In August 2010, the Company and Silicon Valley Bank entered into a Loan and Security Agreement, as amended, and other definitive documentation for a $35 million secured credit facility. The Loan and Security Agreement requires us to obtain a prior written consent from Silicon Valley Bank when we determine to pay any dividends on or make any distribution with respect to our common stock. See “Liquidity and Capital Resources” in Item 7 of Part II included in this report for further information on the covenants under the secured credit facility. Any future determination to pay cash dividends will be subject to the above restriction as well as restrictions under any other existing indebtedness at the discretion of our Board of Directors and will be dependent upon our financial condition, results of operations, capital requirements, and other factors the Board of Directors deems relevant.

Recent Sales of Unregistered Securities

None.

Use of Proceeds from Sales of Registered Securities

None.

Purchases of Equity Securities by the Issuer and Affiliated Purchasers

We did not repurchase any of our outstanding equity securities during the most recent quarter covered by this report.

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The following selected financial information as of and for the dates and periods indicated have been derived from our audited consolidated financial statements. The information set forth below is not necessarily indicative of results of future operations, and should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” in Part II, Item 7 of this report and our consolidated financial statements and related notes included elsewhere in this report.

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The following discussion of our financial condition and results of operations should be read together with our consolidated financial statements and related notes included in Part IV, Item 15 of this report. This discussion contains forward-looking statements that involve risks and uncertainties. As a result of many factors, such as those set forth under the section entitled “Risk Factors” in Item 1A and elsewhere in this report, our actual results may differ materially from those anticipated in these forward-looking statements.

We are one of the largest online providers of aftermarket auto parts, including body parts, engine parts, and performance parts and accessories. Our user-friendly websites provide customers with a broad selection of SKUs, with detailed product descriptions and photographs. Our proprietary product database maps our SKUs to product applications based on vehicle makes, models and years. We principally sell our products to individual consumers through our network of websites and online marketplaces. Our flagship websites are located at www.autopartswarehouse.com, www.partstrain.com, www.jcwhitney.com, www.stylintrucks.com, www.AutoMD.com and our corporate website is located at www.usautoparts.net. We believe our strategy of disintermediating the traditional auto parts supply chain and selling products directly to customers over the Internet allows us to more efficiently deliver products to our customers while generating higher margins.

Our History. We were formed in Delaware in 1995 as a distributor of aftermarket auto parts and launched our first website in 2000. We rapidly expanded our online operations, increasing the number of SKUs sold through our e-commerce network, adding additional websites, improving our Internet marketing proficiency and commencing sales in online marketplaces. Additionally, in August 2010, through our acquisition of WAG, we expanded our product-lines and increased our customer reach in the DIY automobile and off-road accessories market. As a result, our business has grown since 2000, generating net sales of $327.1 million for fiscal 2011.

International Operations. In April 2007, we established offshore operations in the Philippines. Our offshore operations allow us to access a workforce with the necessary technical skills at a significantly lower cost than comparably experienced U.S.-based professionals. Our offshore operations are responsible for a majority of our website development, catalog management, and back office support. Our offshore operations also house our main call center. We had 1,005 employees in the Philippines as of December 31, 2011. In addition to our operations in the Philippines, we have a Canadian subsidiary to facilitate sales of our products in Canada; the subsidiary has no distribution center or employees. We also ship parts directly to Canada and through a freight forwarding partner throughout the world. In 2011, we shipped auto parts to over 160 different countries. We believe that the cost advantages of our offshore operations provide us with the ability to grow our business in a cost-effective manner, and we expect to continue to add headcount and infrastructure to our offshore operations.

Acquisitions. From time to time, we may acquire certain businesses, websites, domain names, or other assets. In the third quarter of fiscal 2009, we completed the acquisition of the assets of a small website and the related domain names which further expanded and enhanced our product offering and our ability to reach more customers. In the first quarter of fiscal 2010, we completed two additional website and domain name asset acquisitions, which increased our net sales and internet traffic. In August 2010, Go Fido, Inc., a wholly-owned subsidiary of ours, completed the purchase of all of the outstanding capital stock of Automotive Specialty Accessories and Parts, Inc. and its wholly-owned subsidiary Whitney Automotive Group, Inc. (referred to herein as “WAG”). WAG’s Midwest

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facility expanded our distribution network and the merchandise WAG offers extended our go-to market product-lines into all terrain vehicles, recreational vehicles and motorcycles, as well as provides us with deep product knowledge into niche segments like Jeep, Volkswagen and trucks. This expansion of our product line increases our customer reach in the DIY automobile and off-road accessories market. The Company believes that the combination of WAG’s established brands and focus on the customer experience, coupled with the Company’s capacity to compete online, creates opportunity for growth. Related to the WAG acquisition, the Company has incurred acquisition and integration related costs of $3.1 million and $7.4 million for the fiscal year ended January 1, 2011and December 31, 2011, respectively. These costs included one-time contract cancellation costs of $1.5 million that the Company recorded in September 2011, for terminating WAG’s sublease agreement related to its former corporate offices located in Chicago, Illinois. No significant integration costs are anticipated in the future, as such the majority of the acquisition and integration related costs have been paid as of December 31, 2011. Since the WAG acquisition, certain residual WAG operations have been separately accounted for during the integration process. These operations relate to certain WAG product revenues, the related operating costs and integration costs. We have presented such residual WAG operations for purposes of providing comparable financial information for the impacted fiscal years ended 2010 and 2011. We will not provide this information going forward into 2012, since 2011 represented a full year with these residual WAG operations and will thus be more comparable to 2012. We expect such revenues and expenses that directly relate to WAG products will gradually decrease over fiscal 2012. For additional information, see “Note 5 – Business Combination” of the Notes to Consolidated Financial Statements, included in Part IV, Item 15 of this report. We may pursue additional acquisition opportunities in the future to increase our share of the aftermarket auto parts market or expand our product offering.

Executive Summary

For the fiscal year 2011, the Company generated net sales of $327.1 million, compared with $262.3 million for fiscal 2010, representing an increase of 25%. Excluding $83.4 million and $39.1 million of net sales from WAG in fiscal 2011 and 2010, respectively, our net sales for fiscal 2011 and 2010 were $243.7 million and $223.2 million, respectively, for an increase of 9% over the prior year. Net loss for fiscal 2011 was $15.1 million, or $0.50 per share, which included a non-cash write-down of intangibles and restructuring charges related to WAG of $3.4 million (net of a $1.7 million tax benefit) and $7.4 million, respectively, and $0.5 million of legal expenses to protect intellectual property. This compares to a net loss of $13.9 million, or $0.46 per share for fiscal 2010, which included $3.1 million of restructuring charges related to WAG, and $2.3 million of legal expenses to protect intellectual property. Earnings per share for fiscal 2011 and 2010 also included amortization expense related to intangibles of $3.7 million or $0.12 per share and $2.8 million or $0.09 per share, respectively. We generated Adjusted EBITDA (Earnings before Interest, Taxes, Depreciation, and Amortization plus current year’s share-based compensation expense, legal costs to enforce intellectual property rights, restructuring expenses related to acquisition and a fiscal 2010 only charge for change in revenue recognition) of $16.3 million in fiscal 2011 compared to $19.5 million in fiscal 2010. Adjusted EBITDA excludes share-based compensation expense of $2.6 million in fiscal 2011 and $2.7 million in fiscal 2010. Adjusted EBITDA is presented because such measure is used by rating agencies, securities analysts, investors and other parties in evaluating the Company. It should not be considered, however, as an alternative to operating income as an indicator of the Company’s operating performance or as an alternative cash flows as measures of the Company’s overall liquidity as presented in the Company’s consolidated financial statements. Further, the Adjusted EBITDA measure shown for the Company may not be comparable to similarly titled measures used by other companies.

To understand revenue generation through our network of e-commerce websites, we monitor several key business metrics, including the following:

Unique Visitors: A unique visitor to a particular website represents a user with a distinct IP address that visits that particular website. We define the total number of unique visitors in a given month as the sum of unique visitors to each of our websites during that month. We measure unique visitors to understand the volume of traffic to our websites and to track the effectiveness of our online marketing efforts. The number of unique visitors has historically varied based on a number of factors, including our marketing activities and seasonality. We believe an increase in unique visitors to our websites will result in an increase in the number of orders. We seek to increase the number of unique visitors to our websites by attracting repeat customers and improving search engine marketing and other internet marketing activities.

Total Number of Orders: We monitor the total number of orders as an indicator of future revenue trends. We recognize revenue associated with an order when the products have been delivered, consistent with our revenue recognition policy.

Average Order Value: Average order value represents our net sales on a placed orders basis for a given period of time divided by the total number of orders recorded during the same period of time. We seek to increase the average order value as a means of increasing net sales. Average order values vary depending upon a number of factors, including the components of our product offering, the order volume in certain online sales channels, macro-economic conditions, and the general level of competition online.

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The tables below reconcile net (loss) income to consolidated Adjusted EBITDA and U.S. Auto Parts (“USAP”) excluding the WAG acquisition for the periods presented (in thousands):

Basis of Presentation

Net Sales. Online and offline sales represent two different sales channels for our products. We generate online net sales primarily through the sale of auto parts to individual consumers through our network of e-commerce websites and online marketplaces, including online advertising. E-commerce sales are derived from our network of websites, which are company owned and operated. E-commerce and online marketplace sales also include inbound telephone sales through our call center that supports these sales channels. Online marketplaces consist primarily of sales of our products on online auction websites, where we sell through auctions as well as through storefronts that we maintain on these third-party owned websites. We sell advertising and sponsorship positions on our e-commerce websites to highlight vendor brands and offer complementary products and services that benefit our customers. Advertising is targeted to specific sections of the websites and can also be targeted to specific users based on the vehicles they drive. Advertising partners primarily include part vendors, national automotive aftermarket brands, and automobile manufacturers. Our offline sales channel represents our distribution of products directly to commercial customers by selling auto parts to collision repair shops located in Southern California and Virginia. Our offline sales channel also includes the distribution of our Kool-Vue mirror line to auto parts distributors nationwide. We also serve consumers by operating retail outlet stores in Independence, Ohio and LaSalle, Illinois.

Cost of Sales. Cost of sales consists of the direct costs associated with procuring parts from suppliers and delivering products to customers. These costs include product costs offset by purchase discounts, freight and shipping costs and warehouse supplies. Depreciation and amortization are excluded from cost of sales and included in marketing, general and administrative and fulfillment costs as noted below.

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General and Administrative Expense. General and administrative expense consists primarily of administrative payroll and related expenses, payment processing fees, legal and professional fees, amortization of software and other administrative costs. General and administrative expense also includes depreciation and amortization expense and share-based compensation expense.

Marketing Expense. Marketing expense consists of online advertising spend, Internet commerce facilitator fees and other advertising costs, as well as payroll and related expenses associated with our marketing catalog, customer service, and sales personnel. These costs are generally variable and are typically a function of net sales. Marketing expense also includes depreciation and amortization expense and share-based compensation expense.

Fulfillment Expense. Fulfillment expense consists primarily of payroll and related costs associated with our warehouse employees and our purchasing group, facility rent, building maintenance, depreciation and other costs associated with inventory management and our wholesale operations. Fulfillment expense also includes depreciation and amortization expense and share-based compensation expense.

Technology Expense. Technology expense consists primarily of payroll and related expenses of our information technology personnel, the cost of hosting our servers, communications expenses and Internet connectivity costs, computer support and software development. Technology expense also includes share-based compensation expense.

Amortization of Intangibles. Amortization of intangibles consists of the amortization expense associated with our intangible assets, which primarily consist of the intangibles recorded as a result of the WAG acquisition.

Impairment loss on Intangibles. Impairment loss on intangibles consists of a fiscal 2011 non-cash impairment charge related to certain WAG trade name intangible assets.

Interest Income (Expense). Interest income consists primarily of interest income on investments. Interest expense consists primarily of interest expense on our outstanding loan balances and capital leases.

Other Income. Other income consists of miscellaneous income such as gain from disposition of assets.

Critical Accounting Policies and Estimates

Our consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States. The preparation of our financial statements requires us to make estimates and assumptions that affect the reported amounts of assets, liabilities, net sales, costs and expenses, as well as the disclosure of contingent assets and liabilities and other related disclosures. On an ongoing basis, we evaluate our estimates, including, but not limited to, those related to revenue recognition, uncollectible receivables, intangible and other long-lived assets and contingencies. We base our estimates on historical experience and on various other assumptions that we believe to be reasonable under the circumstances, the results of which form the basis for making judgments about carrying values of our assets and liabilities that are not readily apparent from other sources. Actual results could differ from those estimates, and we include any revisions to our estimates in our results for the period in which the actual amounts become known.

We believe the critical accounting policies described below affect the more significant judgments and estimates used in the preparation of our consolidated financial statements. Accordingly, these are the policies we believe are the most critical to aid in fully understanding and evaluating our historical consolidated financial condition and results of operations:

Revenue Recognition. From the Company’s inception of business through the first quarter of fiscal 2010, the Company recognized revenue from product sales when the following four revenue recognition criteria were met: persuasive evidence of an arrangement exists, delivery has occurred (to the common carrier), the selling price is fixed or determinable, and collectability is reasonably assured. These criteria followed the Company’s general policy to recognize revenue according to its shipping terms, which were F.O.B. shipping point. Under this policy, title and risk of loss were transferred to the customer upon delivery to the common carrier, at which time, revenue was recognized.

Although the Company had no legal obligation to compensate the customer, the Company generally replaces the product or reimburses the customer for goods that were lost or damaged in transit and filed a claim to the common carrier for reimbursement for such loss. The Company executed a new pricing agreement with its primary carrier which offered a lower price per delivery and eliminated the Company’s option to file reimbursement claims for product lost or damaged in transit. As a result of this agreement, the Company determined that the risk of loss or damage during transit would be retained by the Company. Therefore, the Company determined that revenue from product sales should be recognized at the delivery date, not the ship date.

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This change in the second quarter of fiscal 2010 resulted in a deferral of $2.0 million of sales revenue and a decrease in cost of goods sold of $1.5 million, which reduced gross profit by $411,000. The Company has recognized revenue upon delivery to the customer starting the second quarter of fiscal 2010.

Revenue from sales of advertising is recorded when performance requirements of the related advertising program agreement are met. For fiscal 2011, the advertising revenue represented approximately 2% of our total revenue.

We evaluated the criteria of Accounting Standards Codification (“ASC”) Topic 605-45 - Revenue Recognition - Principal Agent Considerations (“ASC 605-45”), in determining whether it is appropriate to record the gross amount of product sales and related costs or the net amount earned as commissions. When we are the primary party obligated in a transaction, are subject to inventory risk, have latitude in establishing prices and selecting suppliers or have several but not all of these indicators, revenue is recorded at gross.

Product sales and shipping revenues, net of promotional discounts and return allowances, are recorded when the products are delivered and title passes to customers. Retail items sold to customers are made pursuant to terms and conditions that provide for transfer of both title and risk of loss upon our delivery to the customer. Return allowances, which reduce product revenue by our best estimate of expected product returns, are estimated using historical experience.

Payments received prior to the delivery of goods to customers are recorded as deferred revenue.

We periodically provide incentive offers to our customers to encourage purchases. Such offers include current discount offers, such as percentage discounts off of current purchases and other similar offers. Current discount offers, when accepted by our customers, are treated as a reduction to the purchase price of the related transaction.

Sales discounts are recorded in the period in which the related sale is recognized. Sales return allowances are estimated based on historical amounts and are recorded upon recognizing the related sales. Credits are issued to customers for returned products.

Fair Value Measurements. We account for fair value measurements in accordance with ASC Topic 820 Fair Value Measurements and Disclosures (“ASC 820”), which defines fair value, provides a framework for measuring fair value and provides the disclosure requirements for fair value measurements. ASC 820 also establishes a three-tier fair value hierarchy, which prioritizes the inputs used in measuring fair value. These tiers include: Level 1 - defined as observable inputs such as quoted prices in active markets; Level 2 - defined as inputs other than quoted prices in active markets that are either directly or indirectly observable; and Level 3 - defined as unobservable inputs in which little or no market data exists, therefore requiring an entity to develop its own assumptions.

We have evaluated both Level 2 and Level 3 evidence to measure the fair value of our $2.1 million of ARPS as of December 31, 2011. These investments consist solely of collateralized debt obligations supported by municipal and state agencies; do not include mortgage-backed securities or student loans; have redemption features that call for redemption at 100% of par value; and have a current credit rating of A or AAA. During fiscal 2011, we received partial redemptions at par value on our investments totaling $2.1 million. The fact that there continues to not be an active market as of December 31, 2011 to liquidate 100% of these investments, continues to be the final determination in classifying them as Level 3. We used a discounted cash flow valuation model to estimate the fair value of the securities. As a result of the temporary declines in fair value of our ARPS, which we attribute to liquidity issues rather than credit issues, we have recorded an unrealized loss of $21,000 to accumulated other comprehensive income. If our key assumptions used to determine estimated discounted cash flows change in the future, we may be required to record additional losses.

Inventory. Inventory consists of finished goods available-for-sale. We purchase inventory from suppliers both domestically and internationally, primarily in Taiwan and China. We believe that our products are generally available from more than one supplier, and we maintain multiple sources for many of our products, both internationally and domestically. We offer a broad line of auto parts for automobiles from model years 1965 to 2011. Because of the continued demand for our products, we primarily purchase products in bulk quantities to take advantage of quantity discounts and to ensure inventory availability.

Inventory is accounted for using the first-in first-out (“FIFO”) method and valued at the lower of cost or market value. During this valuation, we are required to make judgments about expected disposition of inventory, generally, through sales, returns to product vendors, or liquidations of obsolete or scrap products, and expected recoverable values of each disposition category based on currently-available information. If actual market conditions are less favorable than those anticipated by management, additional write-down of the value of our inventory may be required.

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Website and Software Development Costs. We capitalize certain costs associated with software developed for internal use according to ASC Topic 350-40- Intangibles – Goodwill and Other – Internal-Use Software (“ASC 350-40”), and ASC Topic 350-50- Intangibles – Goodwill and Other – Website Development Costs (“ASC 350-50”). Under these provisions, we capitalize costs associated with website development and software developed for internal use when both the preliminary project design and testing stage are completed and management has authorized further funding for the project, which it deems probable of completion and to be used for the function intended. Capitalized costs include amounts directly related to website development and software development such as payroll and payroll-related costs for employees who are directly associated with, and who devote time to, the internal-use software project. Capitalization of these costs ceases when the project is substantially complete and ready for its intended use.

Long-Lived Assets and Intangibles. We acquire tangible and intangible assets in the normal course of business. We evaluate the recoverability of the carrying amount of these long-lived assets whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable in accordance with ASC Topic 360- Property, Plant, and Equipment (“ASC 360”). Management assesses potential impairments whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. An impairment loss will result when the carrying value exceeds the undiscounted cash flows estimated to result from the use and eventual disposition of the asset. Impairment losses will be recognized in operating results to the extent that the carrying value exceeds the discounted future cash flows estimated to result from the use and eventual disposition of the asset. We continually use judgment when applying these impairment rules to determine the timing of the impairment tests, undiscounted cash flows used to assess impairments, and the fair value of a potentially impaired asset. The reasonableness of our judgments could significantly affect the carrying value of our long-lived assets. We did not recognize any impairment losses on long-lived assets and intangibles for fiscal 2009, 2010 and 2011.

Goodwill and Indefinite-Lived Intangibles. We account for goodwill under the guidance set forth in ASC Topic 350- Intangibles – Goodwill and Other (“ASC 350”), which specifies that goodwill and indefinite-lived intangibles should not be amortized. We have historically evaluated goodwill and indefinite-lived intangibles for impairment on an annual basis or more frequently if events or circumstances occur that would indicate a reduction in fair value. Our annual impairment testing date is October 31. In addition, we identified a single reporting unit in accordance with ASC 350. The goodwill impairment test is a two-step impairment test. The first step compares the fair value of each reporting unit with its carrying amount including goodwill. We estimate the fair value of the reporting unit based on an equal weighting of two market approaches and an income approach, which utilizes discounted future cash flows. The market approaches utilized market multiples of invested capital from 1) comparable publicly traded companies and 2) comparable transactions. The market multiples from invested capital include revenues, total assets, book equity plus debt and EBITDA. Assumptions critical to the fair value estimates under the discounted cash flow model include discount rates, cash flow projections, projected long-term growth rates and the determination of terminal values. Management has performed a sensitivity analysis on its significant assumptions and has determined that a change in its assumptions within selected sensitivity testing levels would not impact its conclusion. The excess of fair value over carrying value for our reporting unit as of October 31, 2011, the annual testing date, was approximately $50 million, and there would have to be a 38% decrease in the estimated fair value of the reporting unit to fail step1. If the carrying amount exceeds estimated fair value, then the second step of the impairment test is performed to measure the amount of any impairment loss by comparing the implied fair value of the reporting unit to its carrying value. We completed our annual testing and passed the first step of the impairment test. Current guidance, adopted in the fourth quarter of fiscal 2011, provides the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. If, after assessing the totality of events or circumstances, an entity determines it is not more likely than not that the fair value of a reporting unit is less than its carrying amount, then performing the two-step impairment test is unnecessary. We opted to continue to perform the step one test for fiscal 2011 as discussed above. We did not recognize any impairment loss on goodwill and indefinite-lived intangibles for fiscal 2009 and 2010. During 2011, we recorded a non-cash impairment charge on certain WAG trade name intangible assets totaling $5.1 million as further described in “Note 6- Goodwill and Intangibles” of the Notes to Consolidated Financial Statements included in Part IV, Item 15 of this report.

Income Taxes. The Company accounts for income taxes in accordance with ASC Topic740 Income Taxes (“ASC 740”). Under ASC 740, deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. When appropriate, a valuation reserve is established to reduce deferred tax assets, which include tax credits and loss carry forwards, to the amount that is more likely than not to be realized. The ability to realize deferred tax assets depends on the ability to generate sufficient taxable income within the carryback or carryforward periods provided for in the tax law for each applicable tax jurisdiction. We consider the following possible sources of taxable income when assessing the realization of our deferred tax assets:

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The assessment regarding whether a valuation allowance is required or should be adjusted also considers, among other matters, the nature, frequency and severity of recent losses of the combined USAP and WAG operations, forecasts of future profitability, the duration of statutory carryforward periods, our experience with tax attributes expiring unused and tax planning alternatives. In making such judgments, significant weight is given to evidence that can be objectively verified.

Concluding that a valuation allowance is not required is difficult when there is significant negative evidence that is objective and verifiable, such as cumulative losses in recent years. Although we expect that the operations of the recently acquired WAG business and our ability to achieve future profitability of these operations was enhanced by the cost reductions that occurred as a result of the acquisition and subsequent integration efforts, WAG’s historic operating results remain relevant as they are reflective of the industry and the effect of economic conditions. The fundamental businesses and inherent risks in which the WAG business operates did not change from those which existed prior to the acquisition. We utilized a three-year analysis of actual results as the primary measure of cumulative losses in recent years. However, because a substantial portion of those cumulative losses relate to impairment of intangible assets and goodwill, those three-year cumulative results are adjusted for the effect of these items. In addition, the near- and medium-term financial outlook is considered when assessing the need for a valuation allowance.

The valuation of deferred tax assets requires judgment and assessment of the future tax consequences of events that have been recorded in the financial statements or in the tax returns, and our future profitability represents our best estimate of those future events. Changes in our current estimates, due to unanticipated events or otherwise, could have a material effect on our financial condition and results of operations. Prior to the acquisition of WAG, the Company concluded that it was more likely than not that we would realize the deferred tax assets in all jurisdictions. However, with the acquisition of WAG in 2010, based largely on the weight of the combined cumulative three-year adjusted loss position, it was determined that it was not more likely than not that the Company would realize its net deferred tax assets as of January 1, 2011. Therefore, a valuation allowance of $18.3 million was recorded as of January 1, 2011, of which $4.7 million was recorded in relation to WAG in connection with our acquisition in August 2010. Based on the same determination, an additional valuation allowance of $5.7 million was recorded as of December 31, 2011, resulting in a valuation allowance balance of $22.8 million as of December 31, 2011.

If, in the future, we generate taxable income on a sustained basis in jurisdictions where we have recorded full valuation allowances, our conclusion regarding the need for full valuation allowances in these tax jurisdictions could change, resulting in the reversal of some or all of the valuation allowances. If our operations generate taxable income prior to reaching profitability on a sustained basis, we would reverse a portion of the valuation allowance related to the corresponding realized tax benefit for that period, without changing our conclusions on the need for a full valuation allowance against the remaining net deferred tax assets.

At December 31, 2011, federal and state net operating loss (“NOL”) carryforwards were $28.3 million and $42.2 million, respectively. Federal NOL carryforwards of $2.7 million were acquired in the acquisition of WAG which are subject to Internal Revenue Code section 382 and limited to an annual usage limitation of $135,000. Additionally the tax benefit of $0.9 million of the federal and state NOL carryforwards which was created by the exercise of stock options will be credited to additional paid-in-capital once recognized. Federal NOL carryforwards expire in 2029 and 2030, while state NOL carryforwards begin to expire in 2016. The state NOL carryforwards expire in the respective tax years as follows (in thousands):

The Company utilizes a two-step approach to recognizing and measuring uncertain tax positions. The first step is to evaluate the tax position for recognition by determining if the weight of available evidence indicates it is more likely than not that the position will be sustained on audit, including resolution of related appeals or litigation processes. The second step is to measure the tax benefit as the largest amount which is more than 50% likely of being realized upon ultimate settlement. We consider many factors when evaluating and estimating our tax positions and tax benefits, which may require periodic adjustments and which may not accurately forecast actual outcomes. As of December 31, 2011, the Company had no material unrecognized tax benefits, interest or penalties related to federal and state income tax matters. The Company’s policy is to record interest and penalties as income tax expense.

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The Company is subject to U.S. federal income tax as well as income tax of foreign and state tax jurisdictions. During fiscal 2010, the Company was audited by the Internal Revenue Service for the year ended December 31, 2008. The audit was concluded with no change. The tax years 2007-2010 remain open to examination by the major taxing jurisdictions to which the Company is subject, except the Internal Revenue Service for which the tax years 2009-2010 remain open. The Company does not anticipate a significant change to the amount of unrecognized tax benefits within the next twelve months.

Share-Based Compensation. The Company accounts for share-based compensation in accordance with ASC Topic 718- Compensation – Stock Compensation (“ASC 718”). ASC 718 requires that all share-based compensation to employees, including grants of employee stock options, be recognized in our financial statements based on their respective grant date fair values. Under this standard, the fair value of each share-based payment award is estimated on the date of grant using an option pricing model that meets certain requirements. We currently use the Black-Scholes option pricing model to estimate the fair value of our share-based payment awards, with the exception of options granted containing market conditions, for which we estimate the fair value using a Monte Carlo model. The Black-Scholes and Monte Carlo valuation models require extensive use of accounting judgment and financial estimates, including estimates of the expected term participants will retain their vested stock options before exercising them, the estimated volatility of our common stock price over the expected term and the number of options that will be forfeited prior to the completion of their vesting requirements. Application of alternative assumptions could produce significantly different estimates of the fair value of share-based compensation and, consequently, the related amount of share-based compensation expense recognized in the Consolidated Statement of Operations could have been significantly different than the amounts recorded. We estimate volatility using historical volatilities of similar public entities. The expected life of the awards is based on a simplified method that defines the life as the average of the contractual term of the options and the weighted average vesting period for all open tranches. Prior to our initial public offering in February 2007, we did not have a history of market prices of our common stock. Due to the limited period time our equity shares have been publicly traded, we do not have sufficient historical exercise data to provide a reasonable basis upon which to estimate expected term. The risk-free interest rate assumption is based on observed interest rates appropriate for the expected life of our awards. The dividend yield assumption is based on our history and expectation of paying no dividends.

Forfeitures are estimated at the time of grant and revised, if necessary, in subsequent periods if actual forfeitures significantly differ from those estimates. We consider many factors when estimating expected forfeitures, including employee class, economic environment, and historical experience. Share-based compensation expense recognized in our financial statements is based on awards that are ultimately expected to vest. If factors change and we employ different assumptions, share-based compensation expense may differ significantly from what we have recorded in the past. If there are any modifications or cancellations of the underlying unvested options, we may be required to accelerate, increase or cancel any remaining unrecognized share-based compensation expense.

We have granted to our employees options to purchase common stock at exercise prices equal to the fair market value of the underlying common stock at the time of each grant, which is the closing market price of our common stock.

Under provisions of ASC 718, we recognized $3.3 million, $2.7 million and $2.6 million of share-based compensation expense for fiscal 2009, fiscal 2010 and fiscal 2011, respectively. At December 31, 2011, the total compensation cost related to unvested stock-based awards granted to employees and non-employee directors under our equity incentive plans but not yet recognized was approximately $3.5 million, net of estimated forfeitures of approximately $1.8 million. This cost will be amortized over a weighted-average period of approximately 2.4 years and will be adjusted for any subsequent changes in estimated forfeitures.

Recent Accounting Pronouncements

See “Note 1 – Summary of Significant Accounting Policies and Nature of Operations” of the Notes to Consolidated Financial Statements, included in Part IV, Item 15 of this report.

Results of Operations

The following table sets forth selected statement of operations data for the periods indicated, expressed as a percentage of net sales:

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The impact of foreign currency is related to our offshore operations in the Philippines and sales of our products in Canada and was not material to our operations.

Fifty-Two Weeks Ended January 1, 2011 Compared to the Fifty-Two Weeks Ended December 31, 2011

Net Sales and Gross Margin

Consolidated net sales increased $64.8 million, or 24.7%, for fiscal 2011 compared to fiscal 2010. Excluding $83.4 million of sales from WAG, the USAP net sales for fiscal 2011 were $243.7 million, an increase of 9.2% over fiscal 2010 net sales, due to increases of $19.5 million, or 9.4%, in online sales and $1.0 million, or 6.2%, in offline sales, which consist of our Kool-Vue™ and wholesale operations. Our online sales consist of our e-commerce, online marketplace sales channels and online advertising. Our e-commerce channel includes our e-commerce websites supported by our call-center sales agents who generate cross-sell and up-sell opportunities. Our online marketplaces consist primarily of auction and other third-party websites. Online advertising is sold on our e-commerce websites.

The USAP increase in online sales is primarily due to a $15.6 million, or 9.0%, increase in e-commerce sales, which resulted from an increase of 211,007, or 11.8%, in total placed orders, an increase of 10.2 million, or 8.9%, in unique visitors, partially offset by a decrease of $2.49, or 2.1%, in average order value from fiscal 2010 to fiscal 2011. The increases in total placed orders and the unique visitors resulted from increased marketing spend driving higher paid traffic and better content on our websites driving more organic traffic. The increases were also attributed to more effective pricing, better catalog data and a better customer experience. Our average order value declined due to increased pricing competition and increased sales of lower cost direct sourced products.

Consolidated gross profit increased 19.4% from fiscal 2010 to fiscal 2011. Consolidated gross margin declined 1.5% to 32.7% compared to fiscal 2010. Excluding the gross profit from WAG, USAP gross profit was $80.4 million, an increase of 6.1%, and USAP gross margin was 33.0% for fiscal 2011 compared to 34.0% for fiscal 2010. USAP gross margin was unfavorably impacted by a shift from body to engine parts and increased freight expenses.

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Marketing Expense

Marketing expense increased $17.0 million, or 43.9%, for fiscal 2011 compared to fiscal 2010. Excluding $20.7 million of marketing expense from WAG, the USAP marketing expense increased $4.9 million, or 16.4%, from fiscal 2010, primarily due to higher amortization costs related to software deployments and an increase in advertising spend which resulted in higher listing and placement fees paid to commercial and search engine websites such as eBay, Google and MSN.

General and Administrative Expense

General and administrative expense increased $3.3 million or 11.6% for fiscal 2011 compared to fiscal 2010. Excluding $12.9 million from WAG, the USAP general and administrative expense decreased $3.6 million primarily due to lower legal expense and depreciation and amortization.

Fulfillment Expense

Fulfillment expense increased $4.2 million, or 28.2%, for fiscal 2011 compared to fiscal 2010. Excluding $3.9 million of fulfillment expense from WAG, the USAP fulfillment expense increased $2.0 million due to an increase in warehouse labor expense in connection with the WAG integration and higher depreciation and amortization from software deployments.

Technology Expense

Technology expense increased $1.4 million, or 23.2%, for fiscal 2011 compared to fiscal 2010. Excluding $2.3 million of technology expense from WAG, the USAP technology expense increased $0.4 million, however, as a percentage of net sales, fiscal 2011 remained consistent with fiscal 2010.

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Amortization of Intangibles

Amortization of intangibles increased by $0.9 million, or 31.0%, in fiscal 2011, primarily due to a full year of amortization expense in the amount of $3.2 million related to the intangible assets acquired in connection with our acquisition of WAG in August 2010.

Impairment loss on Intangibles

Impairment loss on intangibles consists of a fiscal 2011 non-cash impairment charge related to certain WAG trade name intangible assets in the amount of $5.1 million. See further detail in “Note 6- Goodwill and Intangibles” of the Notes to Consolidated Financial Statements included in Part IV, Item 15 of this report.

Other Expense, Net