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                                                                     Exhibit 8.1

                         BROBECK, PHLEGER & HARRISON LLP
                        4675 MacArthur Court, Suite 1000
                         Newport Beach, California 92660

                               December 10, 1996

Merrill Lynch, Pierce, Fenner & Smith     Bankers Trust Company
 Incorporated                             Four Albany Street, 10th floor
World Financial Center                    New York, NY 10006
North Tower, 15th Floor
New York, NY 10281-1315                   Capital Markets Assurance Corporation
                                          885 Third Avenue
Standard & Poor's Services                New York, NY 10022
25 Broadway
New York, NY 10004                        Moody's Investors Service, Inc.
                                          99 Church Street
                                          New York, NY 10007

          Re:      Onyx Acceptance Grantor Trust 1996-4:
                   Certain Federal Income Tax Issues

Ladies and Gentlemen:

                  We have acted as tax counsel to Onyx Acceptance Financial
Corporation (the "Company") in connection with the preparation of the Company's
Registration Statement on Form S-1 (Registration No. 333-16601) filed by the
Company on behalf of the Onyx Acceptance Grantor Trust 1996-4 (the "Trust") with
the Securities and Exchange Commission on November 22, 1996 and Amendment No. 1
thereto transmitted for filing on December 10, 1996 (collectively, the
"Registration Statement") in connection with the registration under the
Securities Act of 1933, as amended, of Automobile Loan Pass-Through Certificates
(the "Certificates"). The Certificates are to be issued pursuant to a Pooling
and Servicing Agreement relating to the formation of the Trust and the issuance
of the Certificates (the "Pooling and Servicing Agreement") among the Company,
Onyx Acceptance Corporation ("Servicer"), and Bankers Trust Company (the
"Trustee"). Capitalized terms used herein that are not otherwise defined have
the meaning assigned to such terms in the Registration Statement.
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December 10, 1996
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                  In rendering the opinions set forth below, we have examined
forms of the following documents presented to us and are relying (without any
independent investigation thereof) upon the truth and accuracy of the
statements, covenants, representations and warranties set forth therein:

                  1.       The Registration Statement;

                  2.       The Pooling and Servicing Agreement;

                  3.       The Purchase Agreement;

                  4.       The Yield Supplement Agreement; and

                  5.       Such other agreements and documents as we have
                           considered necessary or appropriate for the purpose
                           of rendering the opinions set forth below.

                  In rendering the opinions set forth below, we have relied upon
the following representations and assumptions:

                  1.       The form of agreements supplied to us that we
                           reviewed in connection with rendering our opinions
                           hereunder will be validly executed in substantially
                           the same form in which they have been filed as
                           exhibits to the Registration Statement and will be
                           binding and enforceable in accordance with their
                           terms.

                  2.       All parties will perform under such agreements in
                           accordance with their terms.

                  3.       There are no other or further agreements which would
                           alter, amend or otherwise materially affect the
                           relationships created by or described in the above
                           listed documents or described in the Registration
                           Statement, or which would affect the Seller's
                           interest in the Retained Yield.

                  Our opinions represent only our best judgment regarding the
application of federal income tax laws under the Internal Revenue Code of 1986,
as amended (the "Code"), existing judicial decisions, administrative regulations
and published rulings and procedures. Our opinion is not binding upon the
Internal Revenue Service or the courts, and there is no assurance that the
Internal Revenue Service will not successfully assert contrary positions.
Furthermore, no assurance can be given that future legislative, judicial
decisions or administrative changes, applicable either on a prospective or
retroactive basis, might not materially
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December 10, 1996
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alter our opinions. Nevertheless, we undertake no responsibility to advise you
of any new developments in the application or interpretation of the federal
income tax laws.

                  Based on and subject to the foregoing, we are of the opinion
that:

                  A. The Trust will not be classified as a partnership or as an
association taxable as a corporation for federal income tax purposes and, 
instead, under Subpart E, Part I of Subchapter J of the Code, will be treated 
as a grantor trust and, subject to possible recharacterization of certain 
amounts paid by the Trust to the Servicer, the holders of the Certificates 
will be treated as owning an undivided pro-rata interest in the income and 
corpus of the Trust (other than the Retained Yield);

                  B. The statements in the Prospectus under the headings
"Prospectus Summary -- Tax Status" and "Certain Tax Consequences," to the extent
that they constitute matters of law or legal conclusions with respect thereto,
are correct in all material respects; and

                  C. The Trust will not be subject to California franchise or
income taxation and individual holders of Certificates who are not residents of
or otherwise subject to tax in California will not be subject to California
income taxation on any income earned with respect to their investment in the
Certificates so long as they do not hold the Certificates as an asset of a trade
or business conducted in California.

                  We express no opinion as to other tax issues affecting the
purchasers of the Certificates or the other parties to any of the agreements,
nor does our opinion address state, local or foreign tax consequences that may
result from the transactions.

                  We consent to the use of this opinion as an exhibit to the
Registration Statement and further consent to all references to us in the
Registration Statement, the prospectus constituting a part thereof and any
further amendments thereto. Subject to the foregoing sentence, this opinion is
given as of the date hereof solely for your benefit and may not be relied upon,
circulated, quoted or otherwise referred to for any purpose without our prior
written consent.

                                  Respectfully,


                                  /s/ Brobeck Phleger & Harrison LLP