<PAGE>

                                                                     EXHIBIT 4.6

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

                                                       Dated as of June 17, 2003

                           YIELD SUPPLEMENT AGREEMENT

Wells Fargo Bank Minnesota, National Association
Wells Fargo Center
Sixth and Marquette Avenue
MAC N9311-161
Minneapolis, MN 55479
Attn: Asset Backed Securities Department

Nissan Auto Receivables 2003-B Owner Trust
In care of: Wilmington Trust Company
Rodney Square North
1100 North Market Street
Wilmington, DE 19890
Attn: Nissan Auto Receivables 2003-B Owner Trust

Ladies and Gentlemen:

         Nissan Auto Receivables Corporation II (the "Company") hereby confirms
arrangements made as of the date hereof with you, Wells Fargo Bank Minnesota,
National Association, as Indenture Trustee, and Wilmington Trust Company, as
Owner Trustee for the Nissan Auto Receivables 2003-B Owner Trust (the "Trust"),
for the benefit of the Noteholders, to be effective upon (i) receipt by the
Company of the enclosed copy of this letter agreement (the "Yield Supplement
Agreement"), executed by Nissan Motor Acceptance Corporation ("NMAC"), the
Indenture Trustee and the Owner Trustee, (ii) execution of the Purchase
Agreement, dated as of the date hereof (the "Purchase Agreement"), between the
Company and NMAC, (iii) receipt by NMAC of the payment by the Company of the
purchase price under the Purchase Agreement, and (iv) the receipt by the Company
of the capital contribution of NMAC in connection with the payment of the
purchase price under the Purchase Agreement. Capitalized terms used herein and
not otherwise defined herein shall have the respective meanings given to them in
the Sale and Servicing Agreement, dated as of the date hereof, among NMAC, as
Servicer, the Company, and Nissan Auto Receivables 2003-B Owner Trust, as Issuer
(the "Sale and Servicing Agreement").

         1.       On or prior to each Determination Date, the Servicer shall
notify the Company and the Owner Trustee of the "Yield Supplement Deposit" (as
defined below) for the related Distribution Date, the amount on deposit in the
Yield Supplement Account (as defined below), the Servicing Payment Deposit with
respect to the related Distribution Date and the amount of

                                                                  (Nissan 2003-B
                                             Amended & Restated Trust Agreement)

<PAGE>

reinvestment income during the related Collection Period on the Yield Supplement
Account. The "Yield Supplement Deposit" means, with respect to any Distribution
Date, the amount by which (i) the aggregate amount of interest that would have
been due during the related Collection Period on all Yield Supplemented
Receivables (as defined below) if such Yield Supplemented Receivables bore
interest at the Required Rate (as defined below) exceeds (ii) the amount of
interest accrued on such Yield Supplemented Receivables at their respective APRs
and due during such Collection Period. "Required Rate" means, with respect to
each Collection Period, the sum of (i) the Servicing Rate, (ii) the Class A-4
Interest Rate, and (iii) 0.40%. "Yield Supplemented Receivable" means any
Receivable that has an APR less than the Required Rate.

         2.       On or before the date hereof, the Owner Trustee shall
establish and maintain with the Securities Intermediary and pledge to the
Indenture Trustee a segregated trust account in the name of the Indenture
Trustee for the benefit of the Noteholders (the "Yield Supplement Account") in
accordance with the Securities Account Control Agreement to secure the payment
of interest on the Notes, or such other account as may be acceptable to the
Rating Agencies, and the Trust hereby grants to the Indenture Trustee for the
benefit of the Noteholders a first priority security interest in the Yield
Supplement Account and the monies on deposit and the other property that from
time to time comprise the Yield Supplement Account (including the Initial Yield
Supplement Amount), and any and all proceeds thereof (collectively, the "Yield
Supplement Account Property"). The Indenture Trustee shall possess all of the
rights of a secured party under the UCC with respect thereto. The Yield
Supplement Account Property and the Yield Supplement Account shall be under the
sole dominion and control of the Indenture Trustee. Neither the Company, the
Trust nor any Person claiming by, through or under the Company or the Trust
shall have any right, title or interest in, any control over the use of, or any
right to withdraw from amounts from, the Yield Supplement Account Property or
the Yield Supplement Account. All Yield Supplement Account Property in the Yield
Supplement Account shall be applied by the Relevant Trustee as specified in this
Yield Supplement Agreement and the Sale and Servicing Agreement. The Relevant
Trustee shall, not later than 5:00 P.M., New York City time on the Business Day
preceding each Distribution Date, withdraw from the Yield Supplement Account and
deposit in the Collection Account an amount equal to the Yield Supplement
Deposit plus the amount of reinvestment income on the Yield Supplement Account
for such Distribution Date.

         3.       On or prior to the date hereof, the Company shall make a
capital contribution to the Trust of $10,924,790.32 (the "Initial Yield
Supplement Amount"), by depositing such amount into the Yield Supplement
Account. The amount required to be on deposit in the Yield Supplement Account on
the date of issuance of the Notes and for each Distribution Date until the Notes
of all Classes have been paid in full or the Indenture is otherwise terminated
(the "Required Yield Supplement Amount"), as determined by the Servicer and
notified to the Relevant Trustee, means an amount equal to the lesser of (i) the
aggregate amount of each Yield Supplement Deposit that will become due on each
future Distribution Date, assuming that payments on the Receivables are made on
their scheduled due dates, no Receivable becomes a prepaid Receivable and a
discount rate of 0.75%, and (ii) the Initial Yield Supplement Amount. The
Required Yield Supplement Amount may decline as a result of prepayments or
repayments in full of the Receivables. The Relevant Trustee shall have no duty
or liability to determine the Required Yield Supplement Amount and may fully
rely on the determination thereof by the Servicer. If, on any Distribution Date,
the funds in the Yield Supplement Account are in excess

                                                                  (Nissan 2003-B
                                            Amended & Restated Trust Agreement)

                                       2

<PAGE>

of the Required Yield Supplement Amount for such Distribution Date after giving
effect to all distributions to be made on such Distribution Date, the Relevant
Trustee shall deposit the amount of such excess into the Collection Account for
distribution by the Relevant Trustee in accordance with the terms of Sections
5.06(c), (d), (e) and (h) of the Sale and Servicing Agreement. The Yield
Supplement Account shall be part of the Trust. It is the intent of the parties
that the Yield Supplement Account Property be treated as property of the Trust
for all federal, state and local income and franchise tax purposes. The
provisions of this Yield Supplement Agreement should be interpreted accordingly.
Further, the Trust shall include in its gross income all income earned on the
Yield Supplement Account Property and the Yield Supplement Account.

         4.       All or a portion of the Yield Supplement Account may be
invested and reinvested in the manner specified in Section 5.08 of the Sale and
Servicing Agreement in accordance with written instructions from the Servicer or
the Secured Party (as defined in the Securities Account Control Agreement) under
the Securities Account Control Agreement, as the case may be. All such
investments shall be made in the name of the Relevant Trustee. Earnings on
investment of funds in the Yield Supplement Account shall be deposited in the
Collection Account on each Distribution Date, and losses and any investment
expenses shall be charged against the funds on deposit therein. Upon payment in
full of the Notes under the Indenture, as directed in writing by the Servicer,
the Indenture Trustee will release any amounts remaining on deposit in the Yield
Supplement Account to the Owner Trustee for the benefit of the
Certificateholders, which amounts the Owner Trustee shall deposit into the Trust
Collection Account, and the Company shall have no further obligation to pay to
the Servicer the Servicing Payment Deposit. If for any reason the Yield
Supplement Account is no longer an Eligible Deposit Account, the Relevant
Trustee shall promptly cause the Yield Supplement Account to be moved to another
institution or otherwise changed so that the Yield Supplement Account becomes an
Eligible Deposit Account.

         5.       Our agreements set forth in this Yield Supplement Agreement
are our primary obligations and such obligations are irrevocable, absolute and
unconditional, shall not be subject to any counterclaim, setoff or defense
(other than full and strict compliance by us with our obligations hereunder) and
shall remain in full force and effect without regard to, and shall not be
released, discharged or in any way affected by, any circumstances or condition
whatsoever.

         6.       This Yield Supplement Agreement shall not be amended, modified
or terminated except in accordance with the provisions for amendments,
modifications and terminations of the Sale and Servicing Agreement as set forth
in Section 10.01 of the Sale and Servicing Agreement.

         7.       THIS YIELD SUPPLEMENT AGREEMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE INTERNAL LAWS OF THE STATE OF NEW YORK,
without reference to its conflict of law provisions (other than Section 5-1401
of the General Obligations Law of the State of New York), AND THE OBLIGATIONS,
RIGHTS AND REMEDIES OF THE PARTIES UNDER THIS AGREEMENT SHALL BE DETERMINED IN
ACCORDANCE WITH SUCH LAWS.

         8.       Except as otherwise provided herein, all notices pursuant to
this Yield Supplement Agreement shall be in writing, personally delivered, sent
by telecopier, sent by courier or mailed by certified mail, return receipt
requested, and shall be effective upon receipt

                                                                  (Nissan 2003-B
                                             Amended & Restated Trust Agreement)

                                       3

<PAGE>

thereof. All notices shall be directed as set forth below, or to such other
address or telecopy number or to the attention of such other person as the
relevant party shall have designated for such purpose in a written notice.

                  The Company:

                  Nissan Auto Receivables Corporation II
                  990 West 190th Street
                  Torrance, California 90502
                  Attention: Treasurer
                  Facsimile No.: 310-324-2542

                  Indenture Trustee:

                  Wells Fargo Bank Minnesota, National Association
                  Wells Fargo Center
                  Sixth and Marquette Avenue
                  MAC N9311-161
                  Minneapolis, MN 55479
                  Attn: Asset Backed Securities Department
                  Facsimile No.: 612-667-3464

                  Trust:

                  Nissan Auto Receivables 2003-B Owner Trust
                  In care of: Wilmington Trust Company
                  Rodney Square North
                  1100 North Market Street
                  Wilmington, DE 19890
                  Attn: Nissan Auto Receivables 2003-B Owner Trust

         10.      This Yield Supplement Agreement may be executed in one or more
counterparts and by the different parties hereto on separate counterparts, all
of which shall be deemed to be one and the same document.

         11.      Each of the parties hereto agrees and acknowledges that all of
the rights and interests of the Indenture Trustee hereunder shall be
automatically transferred to the Owner Trustee, and the Owner Trustee shall
succeed to all such rights and interests, upon the payment in full of the Notes
in accordance with the terms of the Indenture and the Sale and Servicing
Agreement.

         If the foregoing satisfactorily sets forth the terms and conditions of
our agreement, please indicate your acceptance thereof by signing in the space
provided below and returning to us the enclosed duplicate original of this
letter.

                                                                  (Nissan 2003-B
                                             Amended & Restated Trust Agreement)

                                       4

<PAGE>

                                    Very truly yours,

                                    NISSAN AUTO RECEIVABLES CORPORATION II

                                    By: /s/ Joji Tagawa
                                        ------------------------------------
                                        Name: Joji Tagawa
                                        Title: Treasurer

Agreed and accepted as of June 17, 2003

NISSAN MOTOR ACCEPTANCE CORPORATION

By: /s/ Steven R. Lambert
    --------------------------------
    Name: Steven R. Lambert
    Title: President

WELLS FARGO BANK MINNESOTA, NATIONAL ASSOCIATION,
  AS INDENTURE TRUSTEE

By: /s/ Marianna C. Stershic
    --------------------------------
    Name: Marianna C. Stershic
    Title: Vice President

NISSAN AUTO RECEIVABLES 2003-B OWNER TRUST

By: WILMINGTON TRUST COMPANY,
not in its individual capacity but solely as
Owner Trustee on behalf of the Trust

By: /s/ Janet R. Havrilla
    --------------------------------
    Name: Janet R. Havrilla
    Title: Financial Services Officer

                                                                  (Nissan 2003-B
                                             Amended & Restated Trust Agreement)

                                       S-1