EXHIBIT 8.1

                      [LETTERHEAD OF O'MELVENY & MYERS LLP]



                                December 15, 2004



Nissan Auto Receivables Corporation II
Nissan Motor Acceptance Corporation
Nissan Auto Receivables Trusts
990 West 190th Street
Torrance, California 90502

      Re:   Nissan Auto Receivables Corporation II
            Nissan Motor Acceptance Corporation
            Nissan Auto Receivables Trusts
            Registration Statement on Form S-3
            Relating to Asset-Backed Securities

Ladies and Gentlemen:

      We have acted as special counsel to Nissan Auto Receivables Corporation II
("NARC II"), a Delaware corporation and wholly-owned limited purpose subsidiary
of Nissan Motor Acceptance Corporation, a California corporation ("NMAC"), and
certain trusts, each of which will be owned initially by NARC II (together with
NARC II, each an "Issuer"), in connection with the Issuer's proposed issuance of
$12,430,343,000 aggregate principal amount of asset-backed notes (the "Notes")
and/or asset-backed certificates (the "Certificates") to be offered pursuant to
a registration statement on Form S-3 relating to the Notes and Certificates
(such registration statement, as amended, the "Registration Statement") being
filed with the Securities and Exchange Commission (the "SEC") concurrently
herewith under the Securities Act of 1933, as amended (the "1933 Act"), and the
rules and regulations promulgated thereunder.

      The Notes for each series will be issued under and pursuant to an
indenture for such series, each between the applicable Issuer and the Indenture
Trustee (as defined in the indenture). The indenture, in the form being filed
with the SEC concurrently herewith as an exhibit to the Registration Statement,
is referred to hereinafter as the "Indenture." The trust agreement, in the form
being filed with the SEC concurrently herewith as an exhibit to the Registration
Statement, is referred to hereinafter as the "Trust Agreement." The sale and
servicing agreement, in the form being filed with the SEC concurrently herewith
as an exhibit to the Registration Statement, is referred to hereinafter as the
"Sale and Servicing Agreement."

      We have examined originals or copies, certified or otherwise identified to
our satisfaction, of the organizational documents of the Issuer, the Indenture,
the Trust Agreement, the Sale and Servicing Agreement, the forms of Notes
included as exhibits to the Indenture, the forms of Certificates included as
exhibits to the Trust Agreement, and such other records, documents and
certificates of the Issuers and public officials and other instruments as we
have deemed necessary for the purpose of this opinion. In addition, we have
assumed that each of the Indenture, the Trust Agreement and the Sale and
Servicing Agreement, as applicable, and as completed for each series, will be
duly authorized, executed and delivered by each of the respective parties
thereto; that the Notes and Certificates, as applicable, and as completed for
each series, will be duly authorized, executed and delivered substantially in
the forms contemplated by the Indenture, the Trust Agreement or the Sale and
Servicing Agreement, as applicable; and that the Notes and Certificates for each
series will be sold as described in the Registration Statement.

      As special tax counsel to the Issuers, we have advised the Issuers with
respect to certain federal income tax aspects of the proposed issuance of the
Notes and the Certificates after the date hereof as described in the
Registration Statement. Such advice has formed the basis for the description of
selected federal income tax consequences for holders of the Notes and
Certificates that appears under the heading "CERTAIN FEDERAL INCOME TAX
CONSEQUENCES" in the Prospectus. Such description does not purport to discuss
all possible income tax ramifications of the proposed issuance of the Notes and
Certificates, but with respect to those federal income tax consequences that are
discussed, in our opinion, the description is accurate.

      The opinion set forth above is based on relevant provisions of the United
States Internal Revenue Code of 1986, as amended, Treasury Regulations
thereunder, and interpretations of the foregoing as expressed in court
decisions, administrative determinations, and legislative history as of the date
hereof. These provisions and interpretations are subject to change, which may or
may not be retroactive in effect, that might result in modifications of our
opinion.

      This opinion is furnished by us as special counsel for NARC II or NMAC and
may be relied upon by you only in connection with the transactions contemplated
by Indenture, the Trust Agreement or the Sale and Servicing Agreement, as
applicable. It may not be used or relied upon by you for any other purpose, nor
may copies be delivered to any other person, without in each instance our prior
written consent. This opinion is expressly limited to the matters set forth
above and we render no opinion, whether by implication or otherwise, as to any
other matters. We assume no obligation to update or supplement this opinion to
reflect any facts or circumstances that arise after the date of this opinion and
come to our attention, or any future changes in laws.

      We consent to the filing of this letter as an exhibit to the Registration
Statement and to the reference to this firm under the heading "CERTAIN FEDERAL
INCOME TAX CONSEQUENCES" in the Prospectus and the Prospectus Supplement,
without admitting that we are "experts" within the meaning of the 1933 Act or
the rules or regulations of the Securities and Exchange Commission thereunder,
with respect to any part of the Registration Statement, including this exhibit.

                                        Respectfully submitted,

                                        /s/ O'Melveny & Myers LLP