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                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549
                                _________________

                                    Form 10-K
                                _________________


                                   (Mark One)
       [X] ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

                   For the fiscal year ended December 31, 2004

                                       or

    [ ] TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES
                              EXCHANGE ACT OF 1934

                       For the transition period from to .

                        Commission file number: 333-103244

                       Onyx Acceptance Owner Trust 2004-C
             (Exact name of Registrant as specified in its charter)

                               Delaware 33-0639768
                (State or other jurisdiction of (I.R.S. Employer
              incorporation or organization) Identification Number)

                      Onyx Acceptance Financial Corporation
                       27051 Towne Centre Drive, Suite 100
                            Foothill Ranch, CA 92610
               (Address of principal executive offices)(Zip code)

                                 (949) 465-3900
               (Registrant's telephone number including area code)

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

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 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 amendments to
                              this Form 10-K. [X]

Indicate  by check mark  whether  the  registrant  is an  accelerated  filer (as
               defined in Rule 12b-2 of the Act). Yes [ ] No |X|

                       DOCUMENTS INCORPORATED BY REFERENCE

   8-Ks described herein under Item 15(b) of this annual Report on Form 10-K.


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                           ANNUAL REPORT ON FORM 10-K

                                TABLE OF CONTENTS

PART-I                                                              Page
Item 1. Business.....................................................2
Item 2. Properties...................................................2
Item 3. Legal Proceedings............................................3
Item 4. Submission of Matters to a Vote of Security Holders..........3
PART-II
Item 5. Market for Registrant's Common Equity and Related Stockholder
        Matters: Price Range of Common Stock.........................3
Item 6. Selected Financial Data......................................3
Item 7. Management's Discussion and Analysis of Financial Condition
        and Results of Operations....................................3
Item 7A.Quantitative and Qualitative Disclosures about Market Risk...3
Item 8. Financial Statements and Supplementary Data..................3
Item 9. Changes in and Disagreements with Accountants on Accounting
        and Financial Disclosure.....................................4
Item 9A.Controls and Procedures......................................4
PART-III
Item 10.Directors and Executive Officers of the Registrant...........4
Item 11.Executive Compensation.......................................4
Item 12.Security Ownership of Certain Beneficial Owners and
        Management 1
Item 13.Certain Relationships and Related Transactions...............4
Item 14.Principal Accountant Fees and Services.......................4
PART-IV
Item 15.Exhibits and Reports on Form 8-K.............................5

<PAGE>

                                     PART I


Item 1.  Business

                  Omitted.

Item 2.  Properties

The property of the Trust  includes the Contracts  purchased by Onyx pursuant to
dealer agreements, from automobile dealerships with which Onyx has relationships
and, in general,  all payments  due under the  Contracts on or after the Cut-Off
Dates.  Immediately upon  acquisition,  the Contracts were sold by Onyx to Finco
pursuant to a Second  Amended and Restated  Sale and Servicing  Agreement  dated
November 30, 2001 (the  "Purchase  Agreement").  The Contracts were then sold by
Finco to the Trust  pursuant to a Sale and Servicing  Agreement  dated August 1,
2004. The property of the Trust also includes (i) certain documents  relating to
the  Contracts,  (ii)  certain  monies due under the  Contracts on and after the
Cut-Off Dates,  (iii) security  interests in the Financed Vehicles and the right
to receive  proceeds  from claims on certain  insurance  policies  covering  the
Financed  Vehicles or the obligor  under each related  Contract and the right to
proceeds under a certain blanket  insurance policy  maintained by Onyx, (iv) all
amounts on deposit in the collection account including all eligible  investments
credited  thereto,  (v)  the  benefits  of  an  irrevocable   principle/interest
financial  guaranty  insurance policy issued by XL Capital  Assurance Inc., (vi)
the rights of Finco to cause Onyx to repurchase  certain contracts under certain
circumstances,  and (vii) all  proceeds of the  foregoing.  The  Contracts  were
purchased  by Onyx in the normal  course of business in  accordance  with Onyx's
underwriting  standards,  which  emphasize  the  obligor's  ability  to pay  and
creditworthiness, as well as the asset value of the Financed Vehicle.

As of December 31, 2004, the pool consisted of the following number of Contracts
with the following delinquency characteristics:
<TABLE>

<S>                                                                                             <C>             <C>              <C>
                                                                                         Dollars(2)         Number     Percentage(1)

Contracts Outstanding.............................................................    $ 360,604,093           25,928
Delinquencies(3) 30 - 59 days.....................................................        1,875,203              145           0.52%
60+ days..........................................................................        2,595,350              216           0.72%

(1)      As a percent of dollar amount of contracts outstanding.
(2)      Delinquencies include principal amounts only.
(3)      The period of delinquency is based on the number of days payments are contractually past due.
</TABLE>


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Item 3.  Legal Proceedings
         None.

Item 4.  Submission of Matters to a Vote of Security Holders
         None.

                                     PART II

Item 5. Market for Registrant's Common Equity and Related  Stockholder  Matters:
        Price  Range of Common  Stock
        The  holder of record of all offered Notes as of March 30, 2005, was
        Cede & Co., the nominee of the Depository Trust Company. There is no
        established public trading market for the securities.

Item 6.  Selected Financial Data
         Omitted.

Item 7. Management's  Discussion and Analysis of Financial Condition and Results
        of Operations
         Omitted.

Item 7A.  Quantitative and Qualitative Disclosures about Market Risk
         Omitted.

Item 8.  Financial Statements and Supplementary Data
         Omitted.

Item  9.Changes  in and  Disagreements  with  Accountants  on  Accounting  and
        Financial Disclosure
         None.
Item 9A.Controls and Procedures
         Omitted.
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                                    PART III

Item 10.  Directors and Executive Officers of the Registrant
         Omitted.

Item 11.  Executive Compensation
         Omitted.

Item 12.  Security Ownership of Certain Beneficial Owners and Management
         Omitted.

Item 13.  Certain Relationships and Related Transactions
         Omitted.

Item 14.  Principal Accountant Fees and Serivces
         Omitted



                                     PART IV

Item 15.  Exhibits and Reports on Form 8-K
(a)  The following documents are filed as part of this Report:

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                                    Exhibit
                               Number Description
31.1  Certification pursuant to section 302 of the Sarbanes-Oxley Act of 2002.

99.1  Management's Assertion Concerning Compliance
      with USAP Minimum Servicing Standards

99.2  Report of Independent Accountants

99.3  Schedule of Findings

b)  Reports on Form 8-K

The  following  reports on Form 8-K were filed on behalf of the Onyx  Acceptance
Owner Trust 2004-C during the last quarter of the period covered by this report.


o Form 8-K filed  November  26, 2004.  Item 5 providing  the  Distribution  Date
Statement  for  Distribution  Date of November  15, 2004 and  collection  period
ending October 31, 2004.
o Form 8-K filed  December 20, 2004.  Item 5 providing  the  Distribution  Date
Statement  for  Distribution  Date of December 15, 2004 and  collection  period
ending November 30, 2004.
o Form 8-K filed  January 27, 2005.  Item 5 providing  the  Distribution  Date
Statement  for  Distribution  Date of January 18, 2005 and  collection  period
ending December 31, 2004.

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                                   SIGNATURES

Pursuant to the  requirements of Section 13 or 15(d) of the Securities  Exchange
Act of 1934,  the  registrant has duly caused this Annual Report on Form 10-K to
be signed on its behalf by the undersigned, thereunto duly authorized.

                  ONYX ACCEPTANCE OWNER TRUST 2004-C
                  By: ONYX ACCEPTANCE CORPORATION, as Servicer and Administrator

                  By: /s/ DON DUFFY
                  Don Duffy
                  Chief Financial Officer

Dated: March 30, 2005

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                                INDEX TO EXHIBITS
31.1  Certification pursuant to section 302 of the Sarbanes-Oxley Act of 2002.

99.1  Management's Assertion Concerning Compliance
      with USAP Minimum Servicing Standards

99.2  Report of Independent Accountants

99.3  Schedule of Findings


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