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                                                                    EXHIBIT 10.1










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                             SUPPLEMENTAL INDENTURE

                                      NO. 4


                                       TO


                       INDENTURE DATED AS OF MAY 15, 1999







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                  This SUPPLEMENTAL INDENTURE NO. 4 to INDENTURE (this
"Supplemental Indenture") is entered into among Lear Corporation, a Delaware
corporation (the "Company"), Lear Operations Corporation, a Delaware corporation
("LOC"), Lear Seatings Holdings Corp. # 50, a Delaware corporation ("Lear No.
50"), Lear Corporation EEDS and Interiors, a Delaware corporation ("Lear
Interiors"), Lear Technologies, LLC, a Delaware limited liability company ("Lear
Tech"), Lear Midwest Automotive, Limited Partnership, a Delaware limited
partnership ("LMA"), Lear Automotive (EEDS) Spain S.L., an entity organized
under the laws of Spain ("Lear Spain"), Lear Corporation Mexico, S.A. de C.V.,
an entity organized under the laws of Mexico ("Lear Mexico"), Lear Corporation
(Germany) Ltd., a Delaware corporation ("Lear Germany"), and The Bank of New
York Trust Company, N.A., a national banking association (as successor to The
Bank of New York), as Trustee (the "Trustee").

                                    RECITALS


                  WHEREAS, the Company, LOC, Lear No. 50, Lear Interiors, Lear
Tech, LMA, Lear Spain, Lear Mexico and the Trustee are parties to that certain
Indenture dated as of May 15, 1999, as amended by Supplemental Indenture No. 1
thereto dated as of May 2, 2000, Supplemental Indenture No. 2 thereto dated as
of November 16, 2001 and Supplemental Indenture No. 3 thereto dated as of
January 15, 2002 (the "Indenture"), providing for the issuance and delivery by
the Company of its 7.96% Senior Notes due 2005 which have subsequently been paid
in full (the "7.96% Notes") and its 8.11% Senior Notes due 2009 (the "8.11%
Notes" and, together, with the 7.96% Notes, the "Notes");

                  WHEREAS, Lear Germany, a direct subsidiary of the Company,
will become, concurrently with the execution and delivery of this Supplemental
Indenture, a guarantor under the Principal Credit Facilities; and

                  WHEREAS, pursuant to Section 10.06 of the Indenture, any
subsidiary of the Company that becomes a guarantor under the Principal Credit
Facilities is required to become a Guarantor under the Indenture;

                  NOW, THEREFORE, in consideration of the mutual agreements
contained herein and for other good and valuable consideration, the receipt and
adequacy of which are hereby acknowledged, the parties hereto agree as follows
for the benefit of each other party and for the equal and ratable benefit of the
Holders of the Notes:

                  SECTION 1. GUARANTEE.

                   For value received, Lear Germany hereby agrees to become a
party to the Indenture as a Guarantor under and pursuant to Article 10 of the
Indenture and to jointly and severally unconditionally guarantee to each Holder
and the Trustee (a) the due and punctual payment in full of principal of and
interest on the Notes when due, whether at stated maturity, upon acceleration,
redemption or otherwise, (b) the due and punctual payment in full of interest on
the overdue principal of and, to the extent permitted by law, interest on the
Notes, and (c) the due and punctual payment of

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all other Obligations of the Company and the other Guarantors to the Holders and
the Trustee under the Indenture and the Notes, including, without limitation,
the payment of fees, expenses, indemnification or other amounts.

                  SECTION 2. MISCELLANEOUS.

                  2.1. GOVERNING LAW. THIS SUPPLEMENTAL INDENTURE SHALL BE
GOVERNED BY AND CONSTRUED IN ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK.

                  2.2. Confirmation of the Indenture. Except as amended hereby,
the Indenture shall remain in full force and effect and is hereby ratified and
confirmed in all respects.

                  2.3. Multiple Counterparts. The parties may sign multiple
counterparts of this Supplemental Indenture. Each signed counterpart shall be
deemed an original, but all of them together represent one and the same
agreement.

                  2.4. Separability. Each provision of this Supplemental
Indenture shall be considered separable and if for any reason any provision
which is not essential to the effectuation of the basic purpose of this
Supplemental Indenture shall be invalid, illegal or unenforceable, the validity,
legality and enforceability of the remaining provisions shall not in any way be
affected or impaired thereby.

                  2.5. Headings. The captions of the various section headings of
this Supplemental Indenture have been inserted for convenience of reference
only, are not to be considered a part hereof, and shall in no way modify or
restrict any of the terms or provisions hereof.

                  2.6. The Trustee. The Trustee shall not be responsible in any
manner whatsoever for or in respect of the validity or sufficiency of this
Supplemental Indenture or for or in respect of the recitals contained herein,
all of which recitals are made solely by the Company and the Guarantors.

                  2.7. Definitions. All terms defined in the Indenture shall
have the same meaning in this Supplemental Indenture unless otherwise defined
herein.

                            [signature page follows]



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                  IN WITNESS WHEREOF, the parties hereto caused this
Supplemental Indenture to be duly executed as of this 15th day of December,
2005.


                                 LEAR CORPORATION


                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Executive Vice President and
                                               Chief Financial Officer


                                 LEAR OPERATIONS CORPORATION


                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Vice President


                                 LEAR SEATINGS HOLDINGS CORP. # 50


                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Vice President and
                                               Treasurer


                                 LEAR CORPORATION EEDS AND INTERIORS


                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Vice President and Chief
                                               Financial Officer


                                 LEAR TECHNOLOGIES, LLC
                                 By: Lear Corporation,
                                 its Sole Member

                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Executive Vice President
                                               and Chief Financial Officer


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                                 LEAR MIDWEST AUTOMOTIVE, LIMITED PARTNER
                                 By: Lear Corporation Mendon,
                                 as General Partner


                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Vice President and Treasurer


                                 LEAR AUTOMOTIVE (EEDS) SPAIN S.L.


                                 By:    /s/ Paul Jefferson
                                       ------------------------------
                                       Name:  Paul Jefferson
                                       Title:  Managing Director


                                 LEAR CORPORATION MEXICO, S.A. de C.V.


                                 By:    /s/ James M. Brackenbury
                                       ------------------------------
                                       Name:  James M. Brackenbury
                                       Title: President



                                 LEAR CORPORATION (GERMANY) LTD.


                                 By:    /s/ David C. Wajsgras
                                       ------------------------------
                                       Name:  David C. Wajsgras
                                       Title:  Vice President and Treasurer


                                 THE BANK OF NEW YORK TRUST COMPANY, N.A., as
                                 Trustee


                                 By:    /s/ Roxane Ellwanger
                                       ------------------------------
                                       Name:  Roxane Ellwanger
                                       Title:



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