<PAGE>   1
                                                                   EXHIBIT 10.13


                           MEMBERSHIP PLEDGE AGREEMENT


     This MEMBERSHIP PLEDGE AGREEMENT (this "Agreement") is entered into as of
December 13, 1999 by and between BINGHAM FINANCIAL SERVICES CORPORATION, a
Michigan corporation ("Pledgor") and SUN COMMUNITIES OPERATING LIMITED
PARTNERSHIP, a Michigan Limited Partnership ("Secured Party").

                                    RECITALS:

     A. Pledgor is the sole member of Bloomfield Acceptance Company, L.L.C., and
of Bloomfield Servicing Company, L.L.C.

     B. Pledgor executed and delivered to Sun Communities, Inc. a Term
Promissory Note in the original principal amount of $4,000,000, dated September
30, 1997, which note was assigned and delivered by Sun Communities, Inc. to
Secured Party on December 31, 1997 (the "Term Note").

     C. Pledgor has executed and delivered to Secured Party a Demand Promissory
Note in favor of Secured Party in the original principal amount of $10,000,000
dated March 30, 1999 (the "First Demand Note").

     D. Pledgor has executed and delivered to Secured Party a Demand Promissory
Note in favor of Secured Party in the original principal amount of $50,000,000
dated December 13, 1999 (the "Second Demand Note").

     E. Pledgor has entered into and may in the future enter into various
agreements with Secured Party, pursuant to which Pledgor may have various
contractual, indemnification, warranty and/or other obligations to Secured Party
(the "Contractual Obligations").

     F. To secure the prompt satisfaction by Pledgor of Pledgor's obligations to
Secured Party under the Term Note, the First Demand Note, the Second Demand
Note, the Contractual Obligations and all other obligations of Pledgor to
Secured Party, Pledgor has agreed to execute and deliver this Agreement to
Secured Party.

     NOW, THEREFORE, in consideration of the foregoing, and the mutual covenants
contained herein, the parties agree as follows:

     NOW, THEREFORE, for and in consideration of the foregoing Recitals, the
mutual covenants and agreements set forth below and other good and valuable
consideration, the receipt and adequacy of which are acknowledged, the parties
agree as follows:

     1. DEFINED TERMS. Unless otherwise defined in this Agreement, the following
terms shall have the following meanings, unless the context otherwise requires:


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        "BOOKS" means all books, records, financial information and
correspondence relating to the Collateral.

        "COLLATERAL" has the meaning set forth in Section 2 of this Agreement.

        "COMPANIES" means Bloomfield Acceptance Company, L.L.C., Bloomfield
Servicing Company, L.L.C. and any and all other membership interests in which
Pledgor has or in the future acquires.

        "DISTRIBUTIONS" has the meaning set forth in Section 2 of this
Agreement.

        "EVENT OF DEFAULT" means (i) any material default under this Agreement,
or (ii) any Event of Default (as defined in the Term Note or in the Demand
Note), after taking into account all applicable cure periods.

        "GOVERNING DOCUMENTS" means, with respect to any Person, the certificate
(or articles) of incorporation, by-laws, any agreement among the shareholders,
partners or members of such Person, partnership agreement, certificate of
partnership, articles of organization, operating agreement, all amendments to
any of the foregoing and all other governing documents of such Person.

        "LIEN" means any lien, mortgage, pledge, assignment, security interest,
charge or encumbrance of any kind (including any conditional sale or other title
retention agreement or any lease in the nature thereof) and any agreement to
give or refrain from giving any lien, mortgage, pledge, assignment, security
interest, charge or other encumbrance of any kind.

        "MEMBERSHIP INTERESTS" means all of Pledgor's right, title and interest
in and to the Companies now owned or hereafter acquired.

        "NOTES" means the Term Note, the First Demand Note, the Second Demand
Note and the other promissory notes executed by Pledgor in favor of Secured
Party.

        "OBLIGATIONS" means Pledgor's obligations under the Notes and under the
Contractual Obligations.

        "PERMITTED LIENS" means any Liens both consented to in writing by
Secured Party and identified on the attached Exhibit A.

        "PERSON" OR "PERSONS" means natural persons, corporations, limited
liability companies, limited partnerships, general partnerships, joint stock
companies, joint ventures, associations, companies, trusts, lenders, trust
companies, land trusts, vehicle trusts, business trusts or other organizations,
irrespective of whether they are legal entities, and governments and agencies
and political subdivisions thereof.


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<PAGE>   3


        "PROCEEDS" means whatever is received upon the sale, exchange or other
disposition of the Collateral.

        "REQUIREMENTS OF LAW" means, with respect to any Person, the Governing
Documents of such Person, and any law, treaty, rule or regulation or
determination of an arbitrator or a court or other governmental authority, in
each case applicable to or binding upon such Person or any of its property or to
which such Person or any of its property is subject.

        "SECURED PARTY" has the meaning set forth in the preamble to this
Agreement.

        "UCC" means the Uniform Commercial Code as in effect in the State of
Michigan; provided that if by reason of mandatory provisions of law, the
perfection or effect of perfection or nonperfection of the security interest in
any Collateral or the availability of any remedy under this Security Agreement
is governed by the Uniform Commercial Code in effect in any other jurisdiction,
"UCC" means the Uniform Commercial Code in effect in such other jurisdiction for
purposes of the provisions of this Agreement relating to such perfection or
effect of perfection or nonperfection or availability of such remedy.

     2. GRANT OF SECURITY INTEREST AND PLEDGE. As security for the prompt and
complete payment and performance when due (whether at stated maturity, by
acceleration or otherwise) of all of the Obligations due Secured Party, Pledgor
hereby pledges, assigns, hypothecates, transfers and delivers to Secured Party,
and grants to Secured Party, a first lien on and continuing security interest in
the following property, whether now existing or hereafter acquired
(collectively, the "Collateral"):

        2.1. the Membership Interests;

        2.2. to the extent not otherwise included, all Proceeds of the
     Membership Interests; and

        2.3. any and all distributions, cash, instruments and other property
     from time to time received, receivable or otherwise distributed to Pledgor
     in respect of, or in exchange for, the items described in Sections 2.1 and
     2.2 above ("Distributions").

     If any of the Governing Documents of any of the Companies restricts or
prohibits the pledge or assignment of any of the Membership Interests, this
Agreement shall in all events be construed to be a permitted assignment of all
of Pledgor's right, title and interest in and to all Distributions and Proceeds
with respect to such Membership Interests of Pledgor. In the event that any such
restriction or prohibition shall terminate or be modified in such a way as to
permit the pledge or assignment of such Membership Interests, Pledgor shall
promptly take all actions consistent with the requirements of this Agreement
with respect to Collateral of the same nature not so restricted.


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     3. REPRESENTATIONS AND WARRANTIES. Pledgor represents and warrants that:

        3.1. GOOD TITLE. Pledgor is the owner of the Collateral and has good and
marketable title thereto free and clear of any and all Liens, except for those
granted pursuant to this Agreement and also except for Permitted Liens. There
are no outstanding grants, warrants, options or other agreements with respect to
any of the Collateral, except for those granted pursuant to this Agreement and
also except for Permitted Liens.

        3.2. NOTICE. On the written request of the Secured Party, Pledgor will
execute and deliver notice and directions for payment, in form and substance
satisfactory to Secured Party, to the Companies with respect to this Agreement,
and will deliver to Secured Party in timely fashion, the acknowledgment of each
of them, in form and substance satisfactory to Secured Party, of the assignment
and pledge of the Membership Interests and/or Distributions and Proceeds
pursuant to this Agreement.

        3.3. NO COMPETING FILINGS. No security agreement, financing statement or
equivalent security or lien instrument or continuation statement covering all or
any part of the Collateral is on file or of record in any public office, except
as may have been filed in favor of Secured Party pursuant to this Agreement, or
except for those evidencing Permitted Liens.

All of the foregoing representations and warranties shall be deemed to have been
made on each and every day during which this Agreement is in effect.

     4. RIGHTS AND OBLIGATIONS OF SECURED PARTY.

        4.1. VOTING AND OTHER RIGHTS. So long as no Event of Default has
occurred and is continuing, Pledgor shall be entitled to vote or consent with
respect to the Membership Interests in any manner not inconsistent with this
Agreement and shall have the right to all Distributions. Subject to the previous
sentence, Pledgor hereby grants to Secured Party or its nominee an irrevocable
proxy to exercise all voting and other rights and privileges relating to the
Membership Interests, which proxy shall be effective immediately upon the
occurrence of, and throughout the continuation of, an Event of Default and
written notice to Pledgor of Secured Party's election to exercise such proxy,
and shall be coupled with an interest. Secured Party may exercise all rights and
privileges herein granted with respect to the Membership Interests without
liability and Secured Party shall have no duty to exercise any of the aforesaid
rights or privileges and shall not be responsible for any failure to do so or
delay in so doing. Upon an Event of Default, Secured Party shall have a right to
all Distributions.

        4.2. OBLIGATIONS OF SECURED PARTY. Beyond the exercise of reasonable
care to assure the safe custody of the Collateral while Secured Party has a
security interest in the Collateral, Secured Party shall have no duty or
liability to preserve any rights pertaining to the Collateral. Secured Party
shall not be liable for failure to collect or realize upon the Obligations



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<PAGE>   5

or any Collateral, or any part thereof, or for any delay in so doing, nor shall
it be under any obligation to take any action whatsoever with regard thereto.
Secured Party shall at no time incur any liability to the Companies or others
for any losses, debts or other liabilities or obligations of the Companies
unless Secured Party shall have acquired title to or possession of an interest
in the Companies pursuant to the terms of this Agreement, which title or
interest make it so liable.

        4.3. CONTINUING COMPLIANCE WITH GOVERNING DOCUMENTS. Secured Party shall
not have any obligation or liability under any Governing Documents or otherwise
with respect to the Companies by reason of this Agreement, or the sufficiency of
any performance by any party under the Governing Documents, or to present or
file any claim, or to take any action to collect or enforce any performance or
the payment of any amounts which may have been assigned to it or to which it may
be entitled at any time or times.

        4.4. TERMINATION. Upon full payment, satisfaction and termination of all
of the Obligations, subject to any sale or other disposition by Secured Party of
the Collateral pursuant to this Agreement, the Collateral then held by Secured
Party will be returned to Pledgor and Secured Party will execute and deliver to
Pledgor a UCC termination statement with respect to this Agreement and such
other documents as may be necessary to terminate Secured Party's interest in the
Collateral.

     5. COVENANTS. Pledgor covenants and agrees with Secured Party that until
the Obligations are fully satisfied:

        5.1. FURTHER DOCUMENTATION. At any time and from time to time, upon the
written request of Secured Party, Pledgor will promptly and duly execute and
deliver any and all such further documents and take such further action as
Secured Party may reasonably deem desirable in obtaining the full benefits of
this Agreement and the rights and powers herein granted, including, without
limitation, the filing of any financing or continuation statements under the UCC
with respect to the Liens granted hereby.

        5.2. COMPLIANCE WITH LAWS, ETC. Pledgor will comply, in all material
respects, with all Requirements of Law applicable to the Collateral or any part
thereof; provided, however, that Pledgor may contest any Requirements of Law in
any reasonable manner, including making appropriate reserves, which shall not in
the reasonable opinion of Secured Party adversely affect Secured Party's rights
or the priority of its security interest in the Collateral.

        5.3. PAYMENT OF TAXES. Pledgor will pay and discharge all taxes,
assessments and governmental charges imposed upon the Collateral or in respect
of its income or profits therefrom, as and when such taxes, assessments and
charges are due and payable.


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<PAGE>   6

        5.4. LIMITATION ON LIENS ON COLLATERAL. Pledgor will not create, permit
or suffer to exist, and will defend the Collateral against and take such other
action as is necessary to remove, any Lien on the Collateral other than Liens
claimed from, through or under Secured Party, and will defend the right, title
and interest of Secured Party in and to the Collateral and in and to the
Proceeds and products thereof against the claims and demands of all Persons
whomsoever. Pledgor will not sign or authorize the signing on his behalf of any
financing statement naming him as Pledgor covering all or any portion of the
Collateral, except financing statements naming Secured Party as secured party.

        5.5. LIMITATIONS ON DISPOSITION. Subject to the Governing Documents of
the Companies, Pledgor will not sell, transfer or otherwise dispose of any of
the Collateral, or attempt, offer or contract to do so.

     6. SECURED PARTY'S APPOINTMENT AS ATTORNEY-IN-FACT. Pledgor hereby
irrevocably constitutes and appoints Secured Party and any manager, officer or
agent thereof, with full power of substitution, as his true and lawful
attorney-in-fact with full power and authority in the place and stead of Pledgor
to take any and all appropriate action and to execute any and all documents and
instruments which may be necessary or desirable to accomplish the purposes of
this Agreement. Pledgor hereby ratifies all that Secured Party shall do or cause
to be done by virtue hereof. This power of attorney is a power coupled with an
interest and shall be irrevocable. The powers conferred on Secured Party
hereunder are solely to protect its interests in the Collateral and shall not
impose any duty upon it to exercise any such powers. Secured Party shall be
accountable only for amounts that it actually receives as a result of the
exercise of such powers and Secured Party shall not be responsible to Pledgor
for any act or failure to act, except for Secured Party's gross negligence or
willful misconduct.

     7. REMEDIES. If any Event of Default shall occur and be continuing (but
without limitation of Pledgor's right to satisfy the Obligations prior to any
disposition of the Collateral as hereinafter set forth):

        (a) Secured Party may exercise, in addition to all other rights and
     remedies granted to it in this Security Agreement and in any other
     instrument or agreement securing, evidencing or relating to the
     Obligations, all rights and remedies of a secured party under the UCC
     (whether or not the UCC applies to the affected Collateral).

        (b) Secured Party may sell or cause to be sold the Collateral, or any
     part thereof, at any public or private sale, in one or more sales or lots,
     at such price as Secured Party may deem best, and for cash or on credit or
     for future delivery, without assumption of any credit risk, and the
     purchaser of any or all of the Collateral so sold shall thereafter hold the
     same absolutely, free from any Lien of any kind whatsoever. Pledgor agrees
     that any transfer or sale of the Collateral conducted in conformity with
     reasonable commercial practices of banks, insurance companies or other
     financial institutions disposing of property similar to the Collateral
     shall be deemed to be commercially reasonable. Any



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     requirement of reasonable notice shall be met if such notice is mailed to
     Pledgor at the address set forth in this Agreement at least ten (10)
     business days before the time of the sale or disposition. Any other
     requirement of notice, demand or advertisement for sale, is, to the extent
     permitted by law, waived by Pledgor. Secured Party may, in its own name, or
     in the name of designee or nominee, buy the Collateral at any public sale.
     Secured Party shall have the right to execute any document or form, in its
     name or in the name of Pledgor, which may be necessary or desirable in
     connection with such sale of Collateral.

        (c) Pledgor recognizes that Secured Party may be unable to effect a
     public sale or disposition of any or all of the Membership Interests, or
     any part or portion thereof, by reason of certain prohibitions contained in
     the Securities Act of 1933, as amended (the "Act"), and other applicable
     securities laws, but may be compelled to resort to one or more private
     sales or dispositions thereof to a restricted group of purchasers who will
     be obliged to agree, among other things, to acquire such securities for
     their own account for investment and not with a view to the distribution or
     resale thereof ("Qualified Investors"). Pledgor acknowledges and agrees
     that any such private sale or disposition may result in prices and other
     terms (including the terms of any securities or other property received in
     connection therewith) less favorable to the seller than if such sale or
     disposition were a public sale or disposition. If Secured Party shall
     solicit such offers from two (2) such Qualified Investors, then the
     acceptance by Secured Party of the highest offer obtained therefrom shall
     be deemed to be a commercially reasonable method of disposition of such
     Collateral. Secured Party shall be under no obligation to delay a sale or
     disposition of the Membership Interests to permit the issuer of the
     Membership Interests to register such securities (or trust certificates
     representing such securities) for public sale under the Act, or under
     applicable state securities laws, even if the issuers of the Membership
     Interests would agree to do so.

        (d) Pledgor further agrees to do or cause to be done all such other acts
     and things as may be reasonably necessary to make such sale or sales or
     dispositions of any portion or all of the Membership Interests, or any part
     thereof, valid and binding and in compliance with any and all applicable
     laws, regulations, orders, writs, injunctions, decrees or awards of any and
     all courts, arbitrators or governmental instrumentalities, domestic or
     foreign, having jurisdiction over any such sale or sales or dispositions,
     all at Pledgor's expense.

        (e) Secured Party shall apply the proceeds obtained by application of
     this Section 7 in the following order of priority:

        (i)   To the payment of the reasonable costs, liabilities and advances
              incurred by Secured Party in protecting, exercising and enforcing
              its rights hereunder (including reasonable legal fees);

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        (ii)  To the payment of the accrued interest due under the Obligations,
              as provided for in the Notes;

        (iii) To the payment of unpaid principal under the Obligations, as
              provided for in the Notes; and

        (iv)  The remainder, if any, to Pledgor.

        (f) Pledgor expressly waives and releases all right to direct the order
     in which any of the Collateral shall be sold. Except as provided for
     herein, Pledgor further waives and releases all rights which are waivable
     under Article 9 of the UCC, whether such rights are waivable before or
     after default.

        (g) Pledgor acknowledges and agrees that a breach of any of the
     covenants contained in this Agreement will cause irreparable injury to
     Secured Party and that Secured Party has no adequate remedy at law in
     respect of such breaches and therefore agrees, without limiting the right
     of Secured Party to seek and obtain specific performance of other
     obligations of Pledgor contained in this Agreement, that the covenants of
     Pledgor contained in this Agreement shall be specifically enforceable
     against Pledgor.

     8. COSTS AND EXPENSES. Pledgor shall pay all reasonable costs, fees and
expenses of enforcing Secured Party's security interest in the Collateral, and
any and all excise, property, sales and use taxes imposed by any state, federal
or local authority on any of the Collateral. If Pledgor fails promptly to pay
any portion of the above expenses when due or to perform any other obligation of
Pledgor under this Agreement (after giving effect to applicable cure periods, if
any), Secured Party may, at its option, but shall not be required to, pay or
perform the same and charge Pledgor's account for all reasonable costs and
expenses incurred therefor, and Pledgor agrees to reimburse Secured Party
therefor. All sums so paid or incurred by Secured Party for any of the
foregoing, any and all other reasonable sums for which Pledgor may become liable
hereunder and all reasonable costs and expenses (including reasonable attorneys'
fees, legal expenses and court costs) incurred by Secured Party in enforcing the
security interest of Secured Party in the Collateral or any of its rights or
remedies under this Agreement shall be payable on demand, shall constitute
Obligations, shall bear interest until paid at the highest rate provided in the
Note and shall be secured by the Collateral.

     9. MISCELLANEOUS.


        9.1. NOTICE. Any notice, election, demand, request, consent, approval,
concurrence or other communication given or made under any provision of this
Agreement shall be deemed to have been sufficiently given or made for all
purposes only if it is in writing and it is: (i) delivered personally to the
party to whom it is directed, (ii) sent by first class mail or overnight express
mail, postage and charges prepaid, addressed to the party to whom it is

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directed, at his or its address set forth opposite his or its name below, or
(iii) telecopied to the party to whom it is directed, at his or its address set
forth opposite his or its name below:


                     Pledgor              Bingham Financial Services Corporation
                                          260 East Brown Street
                                          Suite 200
                                          Birmingham, MI 48009
                                          Fax: 248-644-5760

                     Secured Party        Sun Communities Operating Limited
                                            Partnership
                                          31700 Middlebelt Rd., Suite 145
                                          Farmington Hills, MI  48334
                                          Fax:  248-932-3072


Except as otherwise expressly provided in this Agreement, any such notice,
election, demand, request, consent, approval, concurrence or other communication
(i) given or made in the manner indicated in clause (i) above shall be deemed to
be given or made on the day on which it was delivered; (ii) given or made in the
manner indicated in clause (ii) above shall be deemed to be given or made on the
second business day after the day on which it was deposited in a regularly
maintained receptacle for the deposit of the United States' mail, or in the case
of overnight express mail, on the business day immediately following the day on
which it was deposited in a regularly maintained receptacle for the deposit of
overnight express mail; and (iii) given or made in the manner indicated in
clause (iii) above shall be deemed to be given or made when received by the
telecopier owned or operated by the intended recipient thereof. A party may
change his or its address for purposes of this Agreement by giving the other
party notice of such change in the manner hereinbefore provided for the giving
of notices.

        9.2. SEVERABILITY. Wherever possible, each provision of this Agreement
shall be interpreted in such manner as to be effective and valid under
applicable law, but if any provision of this Agreement shall be prohibited by or
invalid under applicable law, such provision shall be ineffective only to the
extent of such prohibition or invalidity, without invalidating the remainder of
such provision or the remaining provisions of this Agreement.

        9.3. INDULGENCES NOT WAIVERS. Secured Party's failure, at any time or
times hereafter, to require performance of any provision of this Agreement by
Pledgor shall not waive, affect or diminish any right of Secured Party
thereafter to demand compliance and performance therewith. Any suspension or
waiver by Secured Party of an Event of Default under this Agreement shall not
suspend, waive or affect any other Event of Default by Pledgor under this
Agreement, whether the same is prior or subsequent thereto and whether of the
same or of a


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different type. None of the undertakings, agreements, warranties, covenants and
representations made by or with respect to Pledgor contained in this Agreement
and no Event of Default by Pledgor shall be deemed to have been suspended or
waived by Secured Party, unless such suspension or waiver is by an instrument in
writing specifying such suspension or waiver and is signed by a duly authorized
representative of Secured Party and delivered to Pledgor.

        9.4. CONSTRUCTION. Neither this Agreement nor any uncertainty or
ambiguity herein shall be construed or resolved against Secured Party, whether
under any rule of construction or otherwise. On the contrary, this Agreement has
been reviewed by each of the parties and their counsel and shall be construed
and interpreted according to the ordinary meaning of the words used so as to
fairly accomplish the purposes and intentions of all parties hereto.

        9.5. MODIFICATION OF AGREEMENT. This Agreement may not be modified,
altered or amended, except by an agreement in writing signed by Secured Party
and Pledgor.

        9.6. SUCCESSORS AND ASSIGNS. This Agreement shall be binding upon and
inure to the benefit of the successors and assigns of Pledgor and Secured Party;
provided, however, that Pledgor may not sell, assign or transfer any of his
rights or obligations hereunder without the prior written consent of Secured
Party.

        9.7. EXECUTION IN COUNTERPARTS. This Agreement may be executed in
counterparts and both such counterparts, taken together, shall constitute one
and the same instrument. Copies (facsimile, photostatic or otherwise) of
signatures to this Agreement shall be deemed to be originals and may be relied
on to the same extent as the originals.

        9.8. SURVIVAL OF AGREEMENTS, REPRESENTATIONS, AND WARRANTIES. All
agreements, representations and warranties, and indemnities made herein, shall
survive the execution and delivery of this Agreement and the making of the loans
secured hereunder.

        9.9. COMPLETE AGREEMENT. This Agreement is intended by the parties as a
final expression of their agreement with respect to the subject matter hereof,
and is intended as a complete statement of the terms and conditions of their
agreement.

        9.10. GOVERNING LAW; CONSENT TO FORUM. THIS AGREEMENT HAS BEEN
NEGOTIATED, EXECUTED AND DELIVERED AT AND SHALL BE DEEMED TO HAVE BEEN MADE IN
OAKLAND COUNTY, MICHIGAN. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF MICHIGAN, WITHOUT REGARD TO ITS
CONFLICT OF LAWS PROVISIONS; PROVIDED, HOWEVER, THAT IF ANY OF THE COLLATERAL
SHALL BE LOCATED IN ANY JURISDICTION OTHER THAN MICHIGAN, THE LAWS OF SUCH
JURISDICTION SHALL GOVERN THE METHOD, MANNER AND PROCEDURE FOR FORECLOSURE OF
SECURED PARTY'S LIEN UPON SUCH COLLATERAL AND THE

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ENFORCEMENT OF SECURED PARTY'S OTHER REMEDIES WITH RESPECT TO SUCH COLLATERAL TO
THE EXTENT THAT THE LAWS OF SUCH JURISDICTION ARE DIFFERENT FROM OR INCONSISTENT
WITH THE LAWS OF MICHIGAN. PLEDGOR HEREBY CONSENTS TO THE JURISDICTION OF ANY
STATE COURT LOCATED WITHIN OAKLAND COUNTY OF THE STATE OF MICHIGAN OR FEDERAL
COURT LOCATED WITHIN THE SOUTHERN DIVISION, EASTERN DISTRICT OF MICHIGAN WITH
SERVICE OF PROCESS TO BE MADE UPON PLEDGOR IN ACCORDANCE WITH APPLICABLE
MICHIGAN OR FEDERAL LAW AS THE CASE MAY BE. PLEDGOR WAIVES ANY OBJECTION TO
JURISDICTION AND VENUE OF ANY ACTION INSTITUTED AGAINST PLEDGORS AS PROVIDED
HEREIN AND AGREES NOT TO ASSERT ANY DEFENSE BASED ON LACK OF JURISDICTION OR
VENUE.

        9.11. WAIVERS BY PLEDGORS. EXCEPT AS OTHERWISE PROVIDED FOR IN THIS
AGREEMENT, THE NOTES OR ANY OF THE GOVERNING DOCUMENTS OF THE COMPANIES TO THE
CONTRARY, PLEDGOR WAIVES: (I) THE RIGHT TO TRIAL BY JURY IN ANY ACTION, SUIT,
PROCEEDING OR COUNTERCLAIM OF ANY KIND ARISING OUT OF OR RELATED TO ANY OF THE
OBLIGATIONS OR THE COLLATERAL; (II) PRESENTMENT, DEMAND AND PROTEST AND NOTICE
OF PRESENTMENT, PROTEST, DEFAULT, NON PAYMENT, MATURITY, RELEASE, COMPROMISE,
SETTLEMENT, EXTENSION OR RENEWAL OF ANY OR ALL COMMERCIAL PAPER, ACCOUNTS,
CONTRACT RIGHTS, DOCUMENTS, INSTRUMENTS, CHATTEL PAPER AND GUARANTIES AT ANY
TIME HELD BY SECURED PARTY ON WHICH PLEDGOR MAY IN ANY WAY BE LIABLE AND HEREBY
RATIFIES AND CONFIRMS WHATEVER SECURED PARTY MAY DO IN THIS REGARD; AND (III)
THE BENEFIT OF ALL VALUATION, APPRAISEMENT AND EXEMPTION LAWS.

        9.12. EXECUTION VOLUNTARY. PLEDGOR ACKNOWLEDGES THAT IT HAS HAD THE
OPPORTUNITY TO SEEK THE ADVICE OF COUNSEL OF ITS CHOICE WITH RESPECT TO THIS
AGREEMENT AND THE TRANSACTIONS CONTEMPLATED HEREBY, AND ACKNOWLEDGES AND AGREES
THAT (A) EACH OF THE WAIVERS SET FORTH HEREIN WERE KNOWINGLY AND VOLUNTARILY
MADE; (B) THE OBLIGATIONS OF SECURED PARTY HEREUNDER AND UNDER THE NOTES,
INCLUDING THE OBLIGATION TO ADVANCE AND LEND FUNDS, SHALL BE STRICTLY CONSTRUED
AND SHALL BE EXPRESSLY SUBJECT TO PLEDGOR'S COMPLIANCE IN ALL RESPECTS WITH THE
TERMS AND CONDITIONS HEREIN SET FORTH; AND (C) NO REPRESENTATIVE OF SECURED
PARTY HAS WAIVED OR MODIFIED ANY OF THE PROVISIONS OF THIS AGREEMENT AS OF THE
DATE HEREOF AND NO SUCH WAIVER OR MODIFICATION FOLLOWING THE DATE HEREOF SHALL
BE EFFECTIVE UNLESS MADE IN ACCORDANCE WITH SECTION 9.5 HEREOF.

                         [SIGNATURES ON FOLLOWING PAGE]


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<PAGE>   12


     IN WITNESS WHEREOF, the parties hereto have executed this Agreement as of
December 13, 1999.


                                    PLEDGOR:

                                    BINGHAM FINANCIAL SERVICES
                                    CORPORATION,  a Michigan corporation


                                    By: /s/ Ronald A. Klein
                                       -----------------------------------------

                                    Its: President and Chief Executive Officer
                                        ----------------------------------------


                                    SECURED PARTY:

                                    SUN COMMUNITIES OPERATING LIMITED
                                    PARTNERSHIP, A MICHIGAN LIMITED
                                    PARTNERSHIP


                                    By:      Sun Communities, Inc., a Maryland
                                             corporation


                                    Its:     General Partner


                                    By:  /s/ Gary  A. Shiffman
                                       -----------------------------------------

                                    Its: President and Chief Executive Officer
                                        ----------------------------------------




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                                    EXHIBIT A


                                      None































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