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                                                                    EXHIBIT 10.6
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                      NISSAN MOTOR ACCEPTANCE CORPORATION,

                               NISSAN-INFINITI LT,

                                   NILT TRUST,

                           NISSAN AUTO LEASING LLC II,

                         NISSAN AUTO LEASE TRUST 2003-A,

                                       and

                         U.S. BANK NATIONAL ASSOCIATION,
                              as Indenture Trustee

                           --------------------------

                           BACK-UP SECURITY AGREEMENT

                          Dated as of October 29, 2003

                           --------------------------

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<TABLE>
<S>      <C>                                                              <C>
                                    ARTICLE I

                                   DEFINITIONS

1.01     Definitions....................................................  2
1.02     Interpretive Provisions........................................  2

                                   ARTICLE II

                                SECURITY INTEREST

2.01     Grant of Security Interest.....................................  2
2.02     Certificate of Title...........................................  3
2.03     Filing of Financing Statements.................................  3
2.04     Use of Collateral..............................................  3
2.05     Further Description of the Collateral..........................  3
2.06     Back-Up Rights of Indenture Trustee............................  4

                                   ARTICLE III

                                  MISCELLANEOUS

3.01     Amendments.....................................................  4
3.02     Governing Law..................................................  4
3.03     Severability of Provisions.....................................  4
3.04     Counterparts...................................................  4
3.05     Successors and Assigns.........................................  4
3.06     Further Assurances.............................................  4
3.07     Limitation of Liability of Owner Trustee.......................  4
3.08     Notices........................................................  5
</TABLE>

                                       i
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                           BACK-UP SECURITY AGREEMENT

         This Back-Up Security Agreement, dated as of October 29, 2003, is among
Nissan Motor Acceptance Corporation, a California corporation ("NMAC"),
Nissan-Infiniti LT, a Delaware statutory trust (the "Titling Trust"), NILT
Trust, a Delaware statutory trust ("NILT Trust"), Nissan Auto Leasing LLC II, a
Delaware limited liability company ("NALL II"), Nissan Auto Lease Trust 2003-A,
a Delaware statutory trust (the "Trust"), and U.S. Bank National Association
("U.S. Bank"), as trustee (the "Indenture Trustee") under the Indenture, dated
as of October 29, 2003 (the "Indenture"), between the Trust and the Indenture
Trustee.

                                    RECITALS

         WHEREAS, NILT Trust, as Grantor and UTI Beneficiary, NMAC, as Servicer,
Wilmington Trust Company, as Delaware Trustee, NILT, Inc., as Trustee, and U.S.
Bank, as Trust Agent, have entered into an amended and restated trust and
servicing agreement, dated as of August 26, 1998 (the "Titling Trust
Agreement"), pursuant to which the Titling Trust was created to, among other
things, take assignments and conveyances of and hold in trust various assets
(the "Trust Assets");

         WHEREAS, the parties to the Titling Trust Agreement supplemented the
Titling Trust Agreement with a 2003-A SUBI Supplement, dated as of October 29,
2003 (together with the Titling Trust Agreement, the "SUBI Trust Agreement"), to
establish a special unit of beneficial interest, the "2003-A SUBI" ("2003-A
SUBI");

         WHEREAS, in connection with the SUBI Trust Agreement a separate
portfolio of leases (the "2003-A Leases"), the vehicles that are leased under
the 2003-A Leases (the "2003-A Vehicles"), and certain other related Trust
Assets have been allocated to the 2003-A SUBI;

         WHEREAS, the Titling Trust has issued a certificate evidencing a 100%
beneficial interest in the 2003-A SUBI (the "2003-A SUBI Certificate") to NILT
Trust;

         WHEREAS, the Trust was formed pursuant to a trust agreement, dated as
of May 13, 2003, as amended and restated as of October 29, 2003 (the "Trust
Agreement"), between NALL II and Wilmington Trust Company, as Owner Trustee;

         WHEREAS, pursuant to the SUBI Certificate Transfer Agreement, dated as
of October 29, 2003 (the "SUBI Certificate Transfer Agreement"), between NILT
Trust and NALL II, NILT Trust has transferred and assigned to NALL II, without
recourse, all of NILT Trust's right, title and interest in the 2003-A SUBI
Certificate;

         WHEREAS, pursuant to the Trust SUBI Certificate Transfer Agreement,
dated as of October 29, 2003 (the "Trust SUBI Certificate Transfer Agreement"),
between NALL II, as transferor (the "Transferor") and the Trust, as transferee,
the Transferor has transferred and assigned to the Trust, without recourse, all
of the Transferor's right, title and interest in the 2003-A SUBI Certificate;

                                                      Back-Up Security Agreement
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         WHEREAS, pursuant to the Indenture, the Trust has granted a security
interest in the 2003-A SUBI Certificate to the Indenture Trustee to secure
payment of the Notes;

         WHEREAS, the parties hereto desire to enter into this Agreement to
provide that if, for any reason, the form of any of the transactions
contemplated by the SUBI Trust Agreement, the 2003-A SUBI Certificate, the Trust
Agreement, the SUBI Certificate Transfer Agreement, the Trust SUBI Certificate
Transfer Agreement or the Indenture (collectively, the "Transfer Documents") is
deemed to constitute a loan by any or all of the Securityholders, secured by a
pledge of the 2003-A SUBI Assets or any interest therein (rather than by the
2003-A SUBI Certificate), each of NMAC, the Titling Trust, NILT Trust, the
Transferor and the Trust shall be deemed to have granted to the Indenture
Trustee a first priority security interest in such assets to secure the Notes.

         NOW, THEREFORE, in consideration of the mutual agreements herein
contained, and of other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, the parties hereto agree as follows:

                                    ARTICLE I
                                   DEFINITIONS

         1.01     Definitions. Capitalized terms used herein that are not
otherwise defined shall have the meanings ascribed thereto in the Agreement of
Definitions, dated as of October 29, 2003, by and among the Trust, as issuer
(the "Issuer"), NILT Trust, as grantor and initial beneficiary (in such
capacity, the "Grantor" and the "UTI Beneficiary," respectively), the Titling
Trust, NMAC, in its individual capacity, as servicer and as administrative agent
(in such capacity, the "Servicer" and the "Administrative Agent," respectively),
NALL II, NILT, Inc., a Delaware corporation, as trustee to the Titling Trust
(the "Trustee"), Wilmington Trust Company, a Delaware banking corporation, as
owner trustee and Delaware trustee (in such capacity, the "Owner Trustee" and
the "Delaware Trustee," respectively) and U.S. Bank, as Indenture Trustee and
trust agent (in such capacity, the "Trust Agent").

         1.02     Interpretive Provisions. For all purposes of this Agreement,
except as otherwise expressly provided or unless the context otherwise requires,
(i) terms used herein include, as appropriate, all genders and the plural as
well as the singular, (ii) references to words such as "herein", "hereof" and
the like shall refer to this Agreement as a whole and not to any particular
part, Article or Section herein, (iii) references to an Article or Section such
as "Article One" or "Section 1.01" shall refer to the applicable Article or
Section of this Agreement, (iv) the term "include" and all variations thereof
shall mean "include without limitation", (v) the term "or" shall include
"and/or" and (vi) the term "proceeds" shall have the meaning ascribed to such
term in the UCC.

                                                      Back-Up Security Agreement

                                       2
<PAGE>

                                   ARTICLE II
                                SECURITY INTEREST

         2.01     Grant of Security Interest.

                  (a)      Each of NMAC, the Titling Trust, NILT Trust, the
Transferor and the Trust hereby grants to the Indenture Trustee a security
interest in all of its present and future right, title and interest in, to and
under (but not, except to the extent required by law, any obligations with
respect to) the following collateral (the "Collateral"): (i) a 100% beneficial
interest in (A) all rights under the 2003-A Leases; (B) to the extent permitted
by applicable law, the 2003-A Vehicles; (C) all other 2003-A SUBI Assets,
including the 2003-A SUBI Collection Account, and (D) all proceeds of the items
described in (i) (A), (B) and (C), including insurance payable by reason of loss
or damage to the 2003-A Vehicles to the extent not applied to making repairs to
the related 2003-A Vehicle or otherwise paid by the Servicer to the Lessee, a
third person or governmental authority as required by law or pursuant to its
normal servicing practices; (ii) the Reserve Account; (iii) all rights and
benefits under the Interest Rate Cap Agreement; and (iv) all proceeds, accounts,
money, general intangibles, instruments, chattel paper, goods, investment
property or other property consisting of, arising from or related to the
foregoing. Such grant is made to secure (i) the payment of all amounts due on
the Securities in accordance with their terms in the priorities of payment set
forth in the Indenture, (ii) the payment of all other sums payable under the
Indenture and (iii) compliance with the provisions of the Indenture.

                  (b)      The Indenture Trustee acknowledges such grant and
assignment, but all parties hereto acknowledge and agree that (i) such grant and
assignment are made solely for protective purposes and without representation or
warranty as to the nature of any of parties' rights in and to the Collateral and
(ii) none of the parties hereto intends to imply in any way that any of the
Transfer Documents should not be interpreted or enforced in accordance with its
respective terms. The Indenture Trustee also acknowledges that it shall have no
claim to any proceeds or assets of the Titling Trust or to any of the Trust
Assets other than the 2003-A SUBI Assets and any present or future proceeds
thereof.

         2.02     Certificate of Title. None of the parties hereto, including
the Titling Trust, shall have any obligation or otherwise be required to make
notation on, or cause to be taken any other action with respect to, any
Certificate of Title for any 2003-A Vehicle to reflect the back-up Lien created
hereby.

         2.03     Filing of Financing Statements. Each of NMAC, the Titling
Trust, NILT Trust, the Transferor and the Trust will from time to time execute,
deliver and file all financing statements and continuation statements reasonably
required or necessary to maintain, perfect or continue the perfection of the
backup Lien created hereby with respect to the 2003-A Leases and the proceeds
thereof and any other Collateral, the perfection of a security interest in which
may be accomplished and continued by the same filings.

         2.04     Use of Collateral. Each of the parties granting a security
interest hereunder may continue to use and deal with its interest in the
Collateral in any lawful manner and may sell items of Collateral in the ordinary
course of its business, subject only to the requirements of the Transfer
Documents and the Servicing Agreement, as appropriate.

         2.05     Further Description of the Collateral. A description of the
2003-A Leases and the 2003-A Vehicles appears on the Schedule of 2003-A Leases
and 2003-A Vehicles.

                                                      Back-Up Security Agreement

                                       3
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         2.06     Back-Up Rights of Indenture Trustee. If a Back-Up Event shall
have occurred and be continuing, the Indenture Trustee may exercise the rights
and remedies with respect to the Collateral of a secured party under the UCC to
the extent permitted by applicable law. Notwithstanding any other provision
hereof, the Indenture Trustee shall have recourse only against the Collateral
and not against any Pledgor hereunder (excluding responsibilities of NMAC solely
as Servicer).

                                   ARTICLE III
                                  MISCELLANEOUS

         3.01     Amendments. This Agreement may be amended by written agreement
among the parties hereto; provided, however, that it may only be amended under
the same circumstances the Trust Agreement could be amended pursuant to Section
12.01 thereof and the Indenture could be amended pursuant to Article Nine
thereof.

         3.02     Governing Law. This Agreement shall be governed by and
construed in accordance with the 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).

         3.03     Severability of Provisions. If any one or more of the
covenants, agreements, provisions or terms of this Agreement shall be for any
reason whatsoever held invalid or unenforceable, then such covenants,
agreements, provisions or terms shall be deemed severable from the remaining
covenants, agreements, provisions and terms of this Agreement, as the same may
be amended or supplemented, and shall in no way affect the validity or
enforceability of the other covenants, agreements, provisions or terms of this
Agreement.

         3.04     Counterparts. This Agreement may be executed in any number of
counterparts, each of which so executed and delivered shall be deemed to be an
original, but all of which counterparts shall together constitute but one and
the same instrument.

         3.05     Successors and Assigns. All covenants and agreements contained
in this Agreement shall be binding upon, and inure to the benefit of, the
parties hereto and their respective permitted successors and assigns.

         3.06     Further Assurances. Each party will perform such acts and
execute and deliver to any other party such additional documents or instruments
as may be reasonably requested in order to effect the purposes of this Agreement
and to better assure and confirm unto the requesting party its rights, powers
and remedies hereunder.

         3.07     Limitation of Liability of Owner Trustee. Notwithstanding
anything contained herein to the contrary, this instrument has been executed by
Wilmington Trust Company not in its individual capacity but solely in its
capacity as Owner Trustee of the Trust and in no event shall Wilmington Trust
Company in its individual capacity or any beneficial owner of the Trust have any
liability for the representations, warranties, covenants, agreements or other
obligations of the Trust hereunder, as to all of which recourse shall be had
solely to the assets of the Trust. For all purposes of this Agreement, in the
performance of any duties or obligations of the Trust

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                                       4
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hereunder, the Owner Trustee shall be subject to, and entitled to the benefits
of, the terms and provisions of Articles Six, Seven and Ten of the Trust
Agreement.

         3.08     Notices. All notices, requests and demands under this
Agreement shall be given in accordance with Section 11.04 of the Indenture. The
address for such purpose of the Titling Trust shall be c/o NILT, Inc., as
Trustee, Wrigley Building, 400 N. Michigan Ave., 2nd Floor, Chicago IL 60611
(telecopier no. (312) 836-6701), Attention: Nissan Auto Lease Trust 2003-A.

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                                       5
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         IN WITNESS WHEREOF, the parties hereto have caused this Agreement to be
duly executed by their respective officers hereto duly authorized, as of the day
and year first above written.

                                          NISSAN MOTOR ACCEPTANCE
                                          CORPORATION

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

                                          NISSAN-INFINITI LT

                                          By: NILT, INC., as Titling Trustee

                                              By: /s/ Patricia M. Child
                                                  ------------------------------
                                              Name: Patricia M. Child
                                              Title: President

                                          NILT TRUST

                                          By: U.S. BANK NATIONAL ASSOCIATION,
                                                 as Managing Trustee

                                              By: /s/ Patricia M. Child
                                                  ------------------------------
                                              Name: Patricia M. Child
                                              Title: Vice President

                                          NISSAN AUTO LEASING LLC II

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

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                                       S-1

<PAGE>

                                    NISSAN AUTO LEASE TRUST 2003-A

                                    By: WILMINGTON TRUST COMPANY,
                                          not in its individual capacity,
                                          but solely as Owner Trustee

                                        By: /s/ Anita E. Dallago
                                            ------------------------------------
                                        Name: Anita E. Dallago
                                        Title: Senior Financial Services Officer

                                    U.S. BANK NATIONAL ASSOCIATION,
                                    as Indenture Trustee

                                    By: /s/ Patricia M. Child
                                        ----------------------------------------
                                        Name: Patricia M. Child
                                        Title: Vice President

                                                      Back-Up Security Agreement

                                       S-2