##### 



EXHIBIT 31

CERTIFICATION OF CHIEF EXECUTIVE
OFFICER

I, John W. Hall, certify that:



| | 1. |  | I have reviewed this quarterly report on Form 10-Q/A of Onyx
Acceptance Corporation;                                                                                                                                                                                                                                
| | -- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | 2. |  | Based on my knowledge, this quarterly report does not contain any
untrue statement of a material fact or omit to state a material fact
necessary to make the statements made, in light of the circumstances
under which such statements were made, not misleading with respect to
the period covered by this report;
|
| | 3. |  | Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows
of the registrant as of, and for, the periods presented in this
quarterly report;                   
|
| | 4. |  | The registrants other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
registrant and we have:                                                                                      



| | a. |  | designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
registrant, including its consolidated subsidiaries, is made known to
us by others within those entities, particularly during the period in
which this report is being prepared;         
| | -- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | evaluated the effectiveness of the registrants disclosure
controls and procedures and presented in this report our conclusions
about the effectiveness of the disclosure controls and procedures, as
of the end of the period covered by this report based on such
evaluation; and                                                                                                    
|
| | c. |  | disclosed in this report any change in the registrants internal
control over financial reporting that occurred during the registrants
most recent fiscal quarter (the registrants fourth fiscal quarter in
the case of an annual report) that has materially affected, or is
reasonably likely to materially affect, the registrants internal
control over financial reporting; and



| | 5. |  | The registrants other certifying officer and I have disclosed, based
on our most recent evaluation of internal control over financial
reporting, to the registrants auditors and the audit committee of
registrants board of directors (or persons performing the equivalent
functions):
| | -- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | a. |  | all significant deficiencies and material weaknesses in the
design or operation of internal control over financial reporting which
are reasonably likely to adversely affect the registrants ability to
record, process, summarize and report financial information; and
| | -- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | any fraud, whether or not material, that involves management or
other employees who have a significant role in the registrants
internal control over financial reporting.                                                                                               

|                         |  |                                               
|------------------------ |  | ----------------------------------------------
|Date:
September 19, 2003 |  |                                               
|                         |  |                                               
|                         |  | /s/ JOHN W. HALL                              
|                         |  |                                               
|                         |  | JOHN W. HALL                                  
|                         |  | President, CEO and Principal Executive Officer





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##### 



CERTIFICATION OF CHIEF FINANCIAL
OFFICER

I, Don P. Duffy, certify that:



| | 1. |  | I have reviewed this quarterly report on Form 10-Q/A of Onyx
Acceptance Corporation;                                                                                                                                                                                                                                
| | -- |  | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | 2. |  | Based on my knowledge, this quarterly report does not contain any
untrue statement of a material fact or omit to state a material fact
necessary to make the statements made, in light of the circumstances
under which such statements were made, not misleading with respect to
the period covered by this report;
|
| | 3. |  | Based on my knowledge, the financial statements, and other financial
information included in this report, fairly present in all material
respects the financial condition, results of operations and cash flows
of the registrant as of, and for, the periods presented in this
quarterly report;                   
|
| | 4. |  | The registrants other certifying officer and I are responsible for
establishing and maintaining disclosure controls and procedures (as
defined in Exchange Act Rules 13a-15(e) and 15d-15(e)) for the
registrant and we have:                                                                                      



| | a. |  | designed such disclosure controls and procedures, or caused such
disclosure controls and procedures to be designed under our
supervision, to ensure that material information relating to the
registrant, including its consolidated subsidiaries, is made known to
us by others within those entities, particularly during the period in
which this report is being prepared;         
| | -- |  | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | evaluated the effectiveness of the registrants disclosure
controls and procedures and presented in this report our conclusions
about the effectiveness of the disclosure controls and procedures, as
of the end of the period covered by this report based on such
evaluation; and                                                                                                    
|
| | c. |  | disclosed in this report any change in the registrants internal
control over financial reporting that occurred during the registrants
most recent fiscal quarter (the registrants fourth fiscal quarter in
the case of an annual report) that has materially affected, or is
reasonably likely to materially affect, the registrants internal
control over financial reporting; and



| | 5. |  | The registrants other certifying officer and I have disclosed, based
on our most recent evaluation of internal control over financial
reporting, to the registrants auditors and the audit committee of
registrants board of directors (or persons performing the equivalent
functions):
| | -- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------



| | a. |  | all significant deficiencies and material weaknesses in the
design or operation of internal control over financial reporting which
are reasonably likely to adversely affect the registrants ability to
record, process, summarize and report financial information; and
| | -- |  | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
|
| | b. |  | any fraud, whether or not material, that involves management or
other employees who have a significant role in the registrants
internal control over financial reporting.                                                                                               

|                         |  |                                
|------------------------ |  | -------------------------------
|                         |  |                                
|                         |  |                                
|Date:
September 19, 2003 |  | /s/ DON P. DUFFY               
|                         |  |                                
|                         |  | DON P. DUFFY                   
|                         |  | Executive Vice President, CFO  
|                         |  | and Principal Financial Officer