LIMITED LIABILITY COMPANY AGREEMENT

                              OF PRIME MBC, L.L.C.

     Organized under the Delaware Limited Liability Company Act (the "Act").

                                   ARTICLE I.

                                NAME AND LOCATION

     Section 1.1. Name. The name of this limited liability company is Prime MBC,
L.L.C. (the "Company").

         Section  1.2.  Members.  The  only  members  of the  Company  upon  the
execution of this Limited Liability Company Agreement (this  "Agreement")  shall
be Prime RVC, Inc, a Delaware  corporation  ("Prime"),  and MBC Holding Company,
L.L.C.,  a  Texas  limited  liability  company  ("MBC").  For  purposes  of this
Agreement,  the  "Members"  shall include such named members and any new members
admitted  pursuant  to the terms of this  Agreement,  but does not  include  any
person or entity who has ceased to be a member in the Company.

     Section 1.3. Principal Office. The principal office of the Company shall be
located in 1301 Capital of Texas Hwy., Suite C-300, Austin, Texas 78746-6550, or
such other location as may be selected by the Members.

     Section 1.4. Registered Agent and Address. The name of the registered agent
and the  address  of the  registered  office of the  Company as set forth in the
Certificate of Formation of the Company are:

                          The Corporation Trust Company
                          1209 Orange Street
                          Wilmington, Delaware 19801

     Section 1.5.  Other  Offices.  Other offices and other  facilities  for the
transaction of business shall be located at such places as the Managers may from
time to time determine.

         Section 1.6  Contribution  Agreement.  The Company was initially formed
with a single  member,  MBC, for the purpose of  consummating  the  transactions
contemplated  by that certain  Contribution  Agreement  dated effective March 1,
2000, by and among Prime,  MBC, the Company,  Mann Berkeley Eye Center,  P.A., a
Texas  professional  association,  Paul Michael Mann,  M.D.,  Ralph G. Berkeley,
M.D.,  Michael  B.  Caplan,  M.D.,  and Mark F.  Micheletti  (the  "Contribution
Agreement").  The parties have executed this Agreement upon  consummation of the
transactions   contemplated  by  the  Contribution  Agreement.   This  agreement
supercedes  and replaces any prior  membership  agreement or other  governing or
organizational document of the Company.

                                   ARTICLE II.

                                   MEMBERSHIP

     Section 2.1. Members' Interests.  The "Membership  Interest" of each Member
is set forth on Exhibit A.

         Section 2.2.  Admission  to  Membership.  The  admission of new Members
shall be only by the vote of the Managers pursuant to Section 8.9 hereof. If new
Members are admitted,  this Agreement  shall be amended to reflect each Member's
revised Membership Interest.

     Section 2.3.  Property  Rights.  No Member shall have any right,  title, or
interest in any of the property or assets of the Company.

     Section  2.4.  Liability  of  Members.  No Member of the  Company  shall be
personally  liable for any debts,  liabilities,  or  obligations of the Company,
including under a judgment decree, or order of court.

         Section 2.5.  Transferability of Membership.  Except as provided below,
Membership  Interests in the Company are  transferable  only with the  unanimous
written  consent  of all  Members.  If such  unanimous  written  consent  is not
obtained when  required,  the  transferee  shall be entitled to receive only the
share of  profits  or other  compensation  by way of  income  and the  return of
contributions  to which  the  transferor  Member  otherwise  would be  entitled.
Notwithstanding the foregoing,  the following shall not be deemed to violate any
provision of this Agreement: (i) the Membership Interests of Prime may be freely
transferred,  without  consent,  to any entity that is then owned or controlled,
directly or indirectly,  by Prime Medical Services, Inc., a Delaware corporation
("PMSI")(or  its successor in interest),  (ii) the  Membership  Interests of any
Member  may be  freely  assigned,  pledged  or  otherwise  transferred,  without
consent,  to  secure  any debt,  liability  or  obligation  owed to Prime by the
Company,  any  Member  or any  entity  affiliated  with the  Company,  (iii) the
Membership Interests of any Member may be freely assigned,  pledged or otherwise
transferred,  without  consent,  in  favor  of the  Lender(s)  under,  or by the
Lender(s)  as a result  of the  enforcement  of any  security  interest  arising
pursuant to, those certain Credit  Facilities (the "Credit  Facilities") of PMSI
and/or  any of PMSI's  subsidiaries,  and (iv) the  pledge by MBC  (pursuant  to
Section 6.3 of the Contribution Agreement) of its right to receive distributions
from the Company in respect of its Membership Interest.

         Section 2.6. Resignation of Members. A Member may not withdraw from the
Company except on the unanimous consent of the remaining  Members.  The terms of
the Members  withdrawal  shall be determined by agreement  between the remaining
Members and the withdrawing Member.


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                                  ARTICLE III.

                                MEMBERS' MEETINGS

         Section  3.1.  Time and Place of Meeting.  All  meetings of the Members
shall be held at such  time and at such  place  within or  without  the State of
Delaware as shall be determined by the Managers.

         Section 3.2. Annual  Meetings.  In the absence of an earlier meeting at
such  time and place as the  Managers  shall  specify,  annual  meetings  of the
Members shall be held at the  principal  office of the Company on the date which
is thirty  (30) days after the end of the  Company's  fiscal year if not a legal
holiday,  and if a legal holiday,  then on the next full business day following,
at 10:00 a.m.,  at which  meeting the Members may transact  such business as may
properly be brought before the meeting.

     Section  3.3.  Special  Meetings.  Special  meetings  of the Members may be
called at any time by any Member.  Business transacted at special meetings shall
be confined to the purposes stated in the notice of the meeting.

         Section 3.4.  Notice.  Written or printed notice stating the place, day
and hour of any Members'  meeting,  and, in the case of a special  meeting,  the
purpose or purposes for which the meeting is called, shall be delivered not less
than ten (10) days nor more than thirty (30) days before the date of the special
meeting,  either  personally  or by mail,  by or at the  direction of the person
calling the meeting, to each Member entitled to vote at such meeting. If mailed,
such notice shall be deemed to be delivered three (3) days after it is deposited
in the United States mail,  postage prepaid,  to the Member at his address as it
appears on the records of the Company at the time of mailing.

         Section 3.5. Quorum. Members present in person or represented by proxy,
holding  more than fifty  percent  (50%) of the total votes which may be cast at
any meeting  shall  constitute  a quorum at all  meetings of the Members for the
transaction  of  business.  If,  however,  such  quorum  shall not be present or
represented at any meeting of the Members, the Members entitled to vote, present
in person or represented by proxy,  shall have power to adjourn the meeting from
time to time,  without notice other than  announcement  at the meeting,  until a
quorum shall be present or represented. When any adjourned meeting is reconvened
and a quorum shall be present or  represented,  any  business may be  transacted
which might have been  transacted at the meeting as originally  noticed.  Once a
quorum is constituted,  the Members present or represented by proxy at a meeting
may  continue  to  transact  business  until  adjournment,  notwithstanding  the
subsequent  withdrawal therefrom of such number of Members as to leave less than
a quorum.

         Section  3.6.  Voting.  Members  shall  only  be  required  to  vote in
instances  or with  respect  to  matters  where  member  voting is  required  by
applicable  law or to the extent  expressly  contemplated  in Section 8.1.  With
respect to any act or  transaction  that  requires a vote by the  Members  under
applicable law, the affirmative  vote of not less than three (3) of the Managers
shall also be  required  in order to  approve  the act or  transaction,  in each
instance. Subject to the foregoing, when a quorum is present at any meeting, the
vote of the Members,  whether  present or  represented by proxy at such meeting,
holding  more than fifty  percent  (50%) of the total votes which may be cast at
any  meeting  shall be the act of the  Members,  unless the vote of a  different
number is required by the Act,  the  Certificate  of  Formation  or this Limited
Liability Company Agreement.  Each Member shall be entitled to one vote for each
percentage point represented by their Membership Interest. Fractional percentage
point  interests  shall be  entitled to a  corresponding  fractional  vote.  The
provisions of this Section shall not  interfere  with the  provisions of Section
8.9 relating to acts or transactions requiring the written approval of three (3)
or more Managers.

         Section  3.7.  Proxy.  Every  proxy must be  executed in writing by the
Member or by his duly authorized  attorney-in-fact,  and shall be filed with the
Secretary of the Company prior to or at the time of the meeting.  No proxy shall
be  valid  after  eleven  (11)  months  from the  date of its  execution  unless
otherwise  provided  therein.  Each proxy shall be  revocable  unless  expressly
provided therein to be irrevocable and unless otherwise made irrevocable by law.

         Section  3.8.  Action  by  Written  Consent.  Any  action  required  or
permitted  to be taken at any  meeting  of the  Members  may be taken  without a
meeting if a consent in  writing,  setting  forth the action so taken,  shall be
signed by all of the Members entitled to vote with respect to the subject matter
thereof,  and such  consent  shall have the same force and effect as a unanimous
vote of Members.

         Section 3.9. Meetings by Conference Telephone.  Members may participate
in and hold  meetings  of Members by means of  conference  telephone  or similar
communications  equipment  by means of which all  persons  participating  in the
meeting  can  hear  each  other,  and  participation  in  such a  meeting  shall
constitute   presence  in  person  at  such  meeting,   except  where  a  person
participates  in the  meeting  for  the  express  purpose  of  objecting  to the
transaction  of any  business  on the ground  that the  meeting is not  lawfully
called or convened.

                                   ARTICLE IV.

                        MEMBERSHIP CAPITAL CONTRIBUTIONS

         Except  for  each  Member's  initial  capital   contribution   made  in
connection with the formation of the Company, no capital  contributions shall be
required  of any  Member  without  the  approval  of all the  Members  to  raise
additional capital, and only then proportionately as to each Member.

                                   ARTICLE V.

                             DISTRIBUTION TO MEMBERS

         At the end of each calendar quarter, subject only to the qualifications
and  limitations  set forth below,  the Company shall  distribute  its available
excess  earnings to its members,  to be divided  among them in  accordance  with
their Membership Interests.  Distributions in kind shall be made on the basis of
agreed value as determined by the Members.  Notwithstanding  the foregoing,  the
Company  may  not  make a  distribution  to its  Members  to  the  extent  that,
immediately  after giving effect to the  distribution,  all  liabilities  of the
Company,  other than  liabilities to the Members with respect to their interests
and  liabilities  for which the  recourse of  creditors  is limited to specified
property of the  Company,  exceed the fair value of the Company  assets;  except
that the fair value of property that is subject to liability for which  recourse
of  creditors  is limited,  shall be included in the Company  assets only to the
extent that the fair value of the property exceeds that liability.

                                   ARTICLE VI.

              ALLOCATION OF NET PROFITS AND LOSSES FOR TAX PURPOSES

         For  accounting  and income tax  purposes,  all items of income,  gain,
loss,  deduction,  and  credit of the  Company  for any  taxable  year  shall be
allocated  among the  Members in  accordance  with their  respective  Membership
Interests,  except as may be otherwise  required by the Internal Revenue Code of
1986, as amended.

                                  ARTICLE VII.

                           DISSOLUTION AND WINDING UP

     Section 7.1.  Dissolution.  Notwithstanding  any  provision of the Act, the
Company shall be dissolved only upon the first of the following to occur:

     (a) Forty (40) years from the date of filing the  Certificate  of Formation
of the Company;

     (b) Written consent of all the then current Members to dissolution;

                  (c) The  bankruptcy of a Member,  unless there is at least one
         remaining Member and such Member or, if more than one remaining Member,
         all remaining Members agree to continue the Company and its business.

         Section 7.2.  Winding Up.  Unless the Company is continued  pursuant to
Section 7.1(c) of this Article VII., in the event of dissolution of the Company,
the Managers (excluding any Manager(s) holding office pursuant to designation by
a Member subject to bankruptcy  proceedings) shall wind up the Company's affairs
as soon  as  reasonably  practicable.  On the  winding  up of the  Company,  the
Managers  shall pay and/or  transfer the assets of the Company in the  following
order:

     (a) In  discharging  liabilities  (including  loans from  Members)  and the
expenses of concluding the Company's affairs; and

     (b) The balance, if any, shall be divided between the Members in accordance
with the Members' Membership Interests.

                                  ARTICLE VIII.

                                    MANAGERS

         Section 8.1. Selection of Managers.  Management of the Company shall be
vested in the  Managers.  Initially,  the Company  shall have five (5) Managers,
being  Ken  Shifrin,  Cheryl  Williams,  Brad  Hummel  (as the  initial  Manager
designees of Prime),  Paul Michael Mann,  M.D. and Ralph G. Berkeley,  M.D., (as
the initial Manager designees of MBC). Thereafter, for so long as there are five
(5)  Managers,  (a)  Prime  shall be  entitled  to  designate  three  (3) of the
Managers;  and (b) MBC shall be entitled to designate  the  remaining two (2) of
the Managers.  Notwithstanding the foregoing,  a Member shall not be entitled to
designate any Manager unless its Membership Interest: (x) has not (other than as
allowed  under Section 2.5 of this  Agreement)  been  transferred,  repurchased,
assigned,  pledged,  hypothecated  or in any way  alienated;  and (y)  equals or
exceeds forty percent (40%) of the aggregate Membership  Interests.  The Members
may, by unanimous vote of all Members,  from time to time,  change the number of
Managers of the Company and remove or add Managers accordingly.  A Manager shall
serve as a Manager until their resignation or removal pursuant to Section 8.2 or
8.3 of this  Article  VIII.  Managers  need  not be  residents  of the  State of
Delaware or Members of the Company.

         Section 8.2. Resignations.  Each Manager shall have the right to resign
at any time upon  written  notice of such  resignation  to the  Members.  Unless
otherwise  specified in such written notice,  the resignation  shall take effect
upon the  receipt  thereof,  and  acceptance  of such  resignation  shall not be
necessary to make same effective.  The Member who designated a resigning manager
shall be entitled to designate  the  successor  thereto and all Members agree to
take such action as may be necessary to cause the election of all such successor
Managers.

         Section 8.3.  Removal of Managers.  Any Manager may be removed,  for or
without cause,  at any time, but only by the Member who designated such Manager,
upon the written notice to all Members.  The Member who designated  such removed
Manager  shall be entitled to designate  the  successor  thereto and all Members
agree to take such action as may be  necessary to cause the election of all such
successor Managers.

         Section  8.4.  General  Powers.  The  business of the Company  shall be
managed by its Managers, which may, by the vote or written consent in accordance
with this  Agreement,  exercise any and all powers of the Company and do any and
all such  lawful  acts and  things  as are not by the Act,  the  Certificate  of
Formation or this Limited Liability Company Agreement directed or required to be
exercised or done by the Members, including, but not limited to, contracting for
or incurring on behalf of the Company debts,  liabilities and other obligations,
without the consent of any other person, except as otherwise provided herein.

     Section 8.5. Place of Meetings.  The Managers of the Company may hold their
meetings,  both  regular  and  special,  either  within or without  the State of
Delaware.

         Section 8.6. Annual Meetings.  The annual meeting of the Managers shall
be held without further notice  immediately  following the annual meeting of the
Members, and at the same place, unless by unanimous consent of the Managers that
such time or place shall be changed.

     Section 8.7. Regular Meetings. Regular meetings of the Managers may be held
without  notice at such time and place as shall from time to time be  determined
by the Managers.

     Section  8.8.  Special  Meetings.  Special  meetings  of the Mangers may be
called by any Manager on seven (7) days notice to each Manager, with such notice
to be given personally, by mail or by telecopy, telegraph or mailgram.

         Section  8.9.  Quorum and Voting.  At all  meetings of the Managers the
presence of at least three (3) Managers  shall be necessary  and  sufficient  to
constitute a quorum for the transaction of business, and the affirmative vote of
at least a majority of the  Managers  present at any meeting at which there is a
quorum shall be the act of the Managers, except as may be otherwise specifically
provided by the Act, the Contribution Agreement, the Certificate of Formation or
this Agreement. If a quorum shall not be present at any meeting of Managers, the
Managers  present there may adjourn the meeting from time to time without notice
other  than  announcement  at the  meeting,  until a quorum  shall  be  present.
Notwithstanding  any  other  Member  or  Manager  voting  or  quorum  provisions
contained  in  this  Agreement,  the  following  acts  or  transactions  by,  or
involving,  the Company shall require the prior written approval of three (3) or
more  Managers  (unless and to the extent a  particular  act or  transaction  is
expressly  required of the Company  pursuant to the terms and  provisions of the
Contribution Agreement or any Transaction Document):

     (a)  Any  amendment  to the  Company's  Certificate  of  Formation  or this
Agreement.

     (b) Mergers,  consolidations  or  combinations  of the Company with another
limited liability company or other entity.

     (c) Purchase by the Company of any interest in the Company, irrespective of
the source of such interest.

                  (d)  Disposition,  sale,  assignment or other  transfer by the
         Company  of any  interest  it owns in the  Company,  except  that  such
         interest may be extinguished  without the approval  required under this
         Article.

                  (e)      Issuance of any interest in the Company to any party.

     (f) Dissolving,  liquidating,  or filing bankruptcy or seeking relief under
any debtor relief law.

     (g)  Election or removal of  officers,  and  establishing  or changing  the
compensation for Managers, officers or other employees.

                  (h) Not making any cash  distributions to its Members that are
         required by this Agreement to be made, or making any  distributions  to
         its  Members  of  cash or  property  that  are  prohibited  under  this
         Agreement.

                  (i) Sale, lease or other transfer of all or substantially  all
         of the  Company's  assets,  or any assets  other  than in the  ordinary
         course of the Company's business.

     (j)  Initiating or settling any  litigation or  regulatory  proceeding,  or
confessing any judgment.

     (k) Hiring or changing the Company's accountants or legal counsel.

                  (l) Opening or closing bank or other depository accounts,  and
         establishing  or  changing  the  signature  withdrawal  authority  with
         respect to any such accounts.

                  (m) Borrowing or incurring any  indebtedness,  other than open
         accounts  payable  to  unaffiliated  third  parties,  or  granting  any
         collateral  or  security  (by way of  guaranty  or  otherwise)  for any
         indebtedness or obligation.

     (n) Engaging in any act or  transaction  not in the ordinary  course of the
Company's business.

                  (o) Purchasing or leasing assets or property, or entering into
         any  contract  or  obligation,  which  obligates  the Company to pay in
         excess  of  $10,000  in  the   aggregate   in  one  or  any  series  of
         installments.

                  (p) Doing any business  other than the conduct of the Business
         (as defined in the  Contribution  Agreement) or causing a change in the
         nature of the business or the legal name of the Company.

     (q) Entering into a transaction  or other action with any Manager,  officer
or Member.

     (r)  Waiving,  refusing to enforce,  amending,  restating,  superseding  or
modifying any of the provisions of this Agreement or any Transaction Document.

                  (s)  Taking  any  other  action  which,  by the  terms of this
         Agreement,   requires   the  approval  or  consent  of  not  less  than
         seventy-five percent (75%) of the Members.

         Any of the  above  stated  actions  taken by the  Company  without  the
necessary manager approval is void ab initio.

         Section 8.10.  Committees.  The Managers  may, by resolution  passed by
eighty percent (80%) of the Managers,  designate  committees,  each committee to
consist  of two or more  Managers  (at  least  one of  which  must be a  Manager
designee  of Prime and one of which must be a Manager  designee  of MBC),  which
committees  shall have such power and authority and shall perform such functions
as may be provided in such  resolution.  Such committee or committees shall have
such name or names as may be  designated  by the Managers and shall keep regular
minutes of their proceedings and report the same to the Managers when required.

         The foregoing paragraph notwithstanding, the Managers shall establish a
Medical  Executive  Committee,  the  size  and  composition  of  which  shall be
established by resolution passed by the affirmative vote of not less than eighty
percent (80%) of the Managers.  Members of the Medical Executive  Committee must
be licensed physicians,  but need not be Members,  Managers,  or officers of the
Company.  The Medical Executive Committee shall meet at such time or times as it
may, by majority  vote of its members,  elect and may adopt  procedures  for the
conduct of its meetings.  The Medical  Executive  Committee shall have authority
and  control  over the  medical  aspects of the  Company's  business,  and shall
provide  advice to the  Managers on decisions  relating to equipment  purchases,
technological  obsolescence,  quality assurance,  credentialing,  and such other
matters as shall be requested by the Managers.  The Medical Executive  Committee
shall have the  authority  to bind the Company  only with respect to the medical
aspects of the Company's business.  Unless otherwise established by a resolution
adopted  by at  least  a  majority  of  the  members  of the  Medical  Executive
Committee,  the majority of the members of the Medical Executive Committee shall
constitute a quorum of the transaction of its business and the affirmative  vote
of the  majority  of  the  members  of the  Medical  Executive  Committee  shall
constitute action validly taken by that body.

         Section  8.11.  Compensation  of Managers.  The  Members,  by unanimous
approval,  shall  have  the  authority  to  provide  that any one or more of the
Managers  shall not be  compensated,  and may, by  unanimous  approval,  fix any
compensation  (which may include  expenses) they elect to pay to any one or more
of the Managers.

         Section  8.12.  Action by  Written  Consent.  Any  action  required  or
permitted  to be  taken  at any  meeting  of the  Managers  or of any  committee
designated  by the Managers may be taken  without a meeting if written  consent,
setting  forth the  action so taken,  is signed by all the  Managers  or of such
committee,  and such consent shall have the same force and effect as a unanimous
vote at a meeting.

         Section 8.13. Meetings by Conference Telephone.  Managers or members of
any committee  designated by the Managers may  participate in and hold a meeting
of the Managers or such  committee by means of  conference  telephone or similar
communications  equipment  by means of which all  persons  participating  in the
meeting  can  hear  each  other,  and  participation  in  such a  meeting  shall
constitute   presence  in  person  at  such  meeting,   except  where  a  person
participates  in the  meeting  for  the  express  purpose  of  objecting  to the
transaction  of any  business  on the ground  that the  meeting is not  lawfully
called or convened.

     Section  8.14.  Liability of Managers.  No Manager of the Company  shall be
personally  liable for any debts,  liabilities,  or  obligations of the Company,
including under a judgment, decree, or order of the court.

         Section 8.15.  Specific Power of Managers.  The Managers shall have the
authority to enter into and execute all  documents in relation to the  formation
of the Company  including,  but not limited to,  issuance of the  Certificate of
Formation and this Limited Liability Company Agreement.

                                   ARTICLE IX.

                                     NOTICES

         Section 9.1. Form of Notice.  Whenever under the provisions of the Act,
the Certificate of Formation or this Limited  Liability Company Agreement notice
is required to be given to any Manager or Member, and no provision is made as to
how such notice shall be given,  notice shall not be construed to mean  personal
notice only, but any such notice may also be given in writing,  by mail, postage
prepaid,  addressed  to such Manager or Member at such address as appears on the
books of the Company, or by telecopy, telegraph or mailgram. Any notice required
or  permitted  to be given by mail  shall be deemed  to be given  three (3) days
after it is deposited, postage prepaid, in the United States mail as aforesaid.

         Section 9.2. Waiver. Whenever any notice is required to be given to any
Manager or Member of the Company under the provision of the Act, the Certificate
of Formation or this Limited  Liability Company  Agreement,  a waiver thereof in
writing signed by the person or persons entitled to such notice,  whether signed
before or after the time stated in such waiver,  shall be deemed  equivalent  to
the giving of such notice.

                                   ARTICLE X.

                                    OFFICERS

         Any Manager may also serve as an officer of the  Company.  The Managers
may  designate  one or more persons who are not Managers of the Company to serve
as officers and may designate the titles of all officers.  The initial  officers
of the  Company  shall be: Ken  Shifrin,  Chairman  of the Board;  Brad  Hummel,
President; Teena Belcik, Vice President,  Secretary and Chief Financial Officer;
and Mark Micheletti,  Vice President.  Unless otherwise provided in a resolution
of the Members or  Managers  the  officers of the Company  shall have the powers
designated  with respect to such offices  under the Delaware  Limited  Liability
Company Act, and any successor statute, as amended from time-to-time.

                                   ARTICLE XI.

                                    INDEMNITY

         Section 11.1.  Indemnification.  The Company shall indemnify any person
who was or is a party or is  threatened  to be made a party  to any  threatened,
pending or  completed  action,  suit or  proceeding,  whether  civil,  criminal,
administrative, arbitrative or investigative, any appeal in such an action, suit
or  proceeding  and any  inquiry  or  investigation  that  could lead to such an
action,  suit or proceeding  (whether or not by or in the right of the Company),
by reason of the fact that such person is or was a manager, officer, employee or
agent of the  Company or is or was  serving at the  request of the  Company as a
director,  manager, officer, partner, venturer,  proprietor,  trustee, employee,
agent or similar  functionary  of another  corporation,  employee  benefit plan,
other enterprise,  or other entity, against all judgments,  penalties (including
excise and similar taxes), fines, settlements and reasonable expenses (including
attorneys'  fees and court  costs)  actually and  reasonably  incurred by him in
connection with such action,  suit or proceeding to the fullest extent permitted
by any  applicable  law,  and such  indemnity  shall inure to the benefit of the
heirs,  executors and administrators of any such person so indemnified  pursuant
to this Article XI. The right to indemnification  under this Article XI shall be
a contract  right and shall not be deemed  exclusive of any other right to which
those seeking  indemnification may be entitled under any law, bylaw,  agreement,
vote of members or disinterested managers or otherwise, both as to action in his
official  capacity  and as to action in  another  capacity  while  holding  such
office.  Any repeal or amendment of this Article XI by the Managers (pursuant to
Section  8.9  hereof)  or by  changes in  applicable  law  shall,  to the extent
permitted by applicable law, be prospective only, and shall not adversely affect
the  indemnification  of any person who may be  indemnified  at the time of such
repeal or amendment.

         Section   11.2.   Indemnification   Not   Exclusive.   The   rights  of
indemnification  and reimbursement  provided for in this Article XI shall not be
deemed  exclusive  of any  other  rights  to which  any such  Manager,  officer,
employee or agent may be  entitled  under the  Certificate  of  Formation,  this
Limited  Liability  Company  Agreement,  agreement  or vote of Members,  or as a
matter of law or otherwise.

         Section  11.3.  Other  Indemnification  Clauses.   Notwithstanding  the
foregoing,   this  Article  XI  shall  not  be  construed  to   contradict   the
indemnification  provisions  of  the  Contribution  Agreement.   Notwithstanding
anything  contained  herein,  this Article XI shall be ineffectual and shall not
permit or require  indemnification for all, or any, losses, costs,  liabilities,
claims or expenses arising, directly or indirectly,  from any action or omission
permitting or requiring indemnification under the Contribution Agreement; and in
no event may any  indemnity be allowed  under this  Agreement or pursuant to any
provision   of  the  Act  for  an  amount  paid  or  payable   pursuant  to  the
indemnification provisions of the Contribution Agreement.

                                  ARTICLE XII.

                                  MISCELLANEOUS

     Section 12.1. Fiscal Year. The fiscal year of the Company shall be fixed by
resolution of the Managers.

     Section 12.2.  Records.  At the expense of the Company,  the Managers shall
maintain  records and accounts of all  operations of the Company.  At a minimum,
the Company shall keep at its principal place of business the following records:

     (a) A  current  list of the name and last  known  mailing  address  of each
Member;

                  (b)      A current list of each Member's Membership Interest;

                  (c) A  copy  of  the  Certificate  of  Formation  and  Limited
         Liability Company Agreement of the Company, and all amendments thereto,
         together with executed copies of any powers of attorney;

     (d) Copies of the Federal,  state, and local income tax returns and reports
for the Company's six most recent tax years; and

     (e) Correct and complete books and records of account of the Company.

         Section 12.3. Seal. The Company may by resolution of the Managers adopt
and have a seal, and said seal may be used by causing it or a facsimile  thereof
to be  impressed  or  affixed or in any manner  reproduced.  Any  officer of the
Company shall have authority to affix the seal to any document requiring it.

     Section 12.4. Agents.  Every Manager and Officer is an agent of the Company
for the purpose of the business. The act of a Manager or Officer,  including the
execution  in the name of the Company of any  instrument  for carrying on in the
usual way the business of the Company, binds the Company.

         Section 12.5. Checks. All checks,  drafts and orders for the payment of
money,  notes  and other  evidences  of  indebtedness  issued in the name of the
Company  shall be  signed  by such  officer,  officers,  agent or  agents of the
Company  and in such  manner  as  shall  from  time to  time  be  determined  by
resolution of the Managers. In the absence of such determination by the Mangers,
such  instruments  shall  be  signed  by  the  Treasurer  or the  Secretary  and
countersigned  by the  President  or a Vice  President  of the  Company,  if the
Company has such officers.

     Section 12.6.  Deposits.  All funds of the Company shall be deposited  from
time to time to the credit of the  Company in such  banks,  trust  companies  or
other depositories as the Managers may select.

     Section 12.7. Annual  Statement.  The Managers shall present at each annual
meeting a full and clear statement of the business and condition of the Company.

         Section 12.8.  Financial  Statements.  As soon as practicable after the
end of each fiscal year of the  Company,  a balance  sheet as at the end of such
fiscal year,  and a profit and loss  statement  for the period  ended,  shall be
distributed  to the  Members,  along with such tax  information  (including  all
information  returns) as may be necessary for the  preparation of each Member of
its Federal,  state and local income tax returns.  The balance  sheet and profit
and loss statement  referred to in the previous  sentence may be as shown on the
Company's federal income tax return.

         Section 12.9. Binding Arbitration.  Any controversy between the parties
regarding  this  Agreement and any claims  arising out of this  Agreement or its
breach  shall be submitted  to  arbitration  by either  party.  The  arbitration
proceedings shall be conducted by a single arbitrator pursuant to the Commercial
Arbitration Rules of the American Arbitration Association. The arbitration shall
be conducted in Dallas,  Texas and the arbitrator  shall have the right to award
actual  damages  and  attorney  fees and costs,  but shall not have the right to
award punitive, exemplary or consequential damages against either party.

                                  ARTICLE XIII.

                                   AMENDMENTS

         Section 13.1.  Amendments.  This  Agreement may be altered,  amended or
repealed and a new limited liability  company agreement may be adopted,  only in
accordance  with the  provisions  of Section 8.9,  but  otherwise at any regular
meeting or at any special meeting called for that purpose,  or by execution of a
written consent in accordance with the provisions of Section 3.8.

         Section 13.2. When Limited  Liability  Company  Agreement Silent. It is
expressly recognized that when the Limited Liability Company Agreement is silent
or in conflict with the  requirements  of the Act as to the manner of performing
any Company function, the provisions of the Act shall control.

                            [Signature page follows]


<PAGE>



S-1

                                SIGNATURE PAGE TO
                       LIMITED LIABILITY COMPANY AGREEMENT

         IN WITNESS WHEREOF,  the undersigned  Members hereby adopt this Limited
Liability  Company  Agreement as the Limited  Liability Company Agreement of the
Company, effective as of the 1st day of March, 2000.

                                                     MBC Holding Company, L.L.C.

                                                     By:
                                  Printed Name:

                                     Title:

                                                     Prime RVC, Inc.
                                                     By:
                                  Printed Name:

                                     Title:


<PAGE>


A-1

                                    EXHIBIT A

                               OWNERSHIP INTERESTS

Name                                                 Ownership Percentage

Prime                                                   60%

MBC                                                     40%