DELAWARE CERTIFICATE OF INCORPORATION

                                       OF

                                 PRIME RVC, INC.

         THE UNDERSIGNED,  acting as the incorporator of a corporation under and
in accordance with the General Corporation Law of the State of Delaware,  hereby
adopts the following Certificate of Incorporation for such corporation:

Article I

         The name of the corporation is Prime RVC, Inc.

Article II

         The purpose for which the  Corporation is organized is the  transaction
of  any or  all  lawful  acts  and  activities  for  which  corporations  may be
incorporated under the General Corporation Law of the State of Delaware.

Article III

         The aggregate  number of shares of capital  stock that the  Corporation
shall have  authority to issue is ten thousand  (10,000),  par value $ $0.01 per
share.  All of such  shares  shall be common  stock of the  corporation.  Unless
specifically  provided  otherwise  herein,  the holders of such shares  shall be
entitled to one vote for each share held in any stockholder vote in which any of
such holders is entitled to participate.

         The  board  of  directors  may  determine  the  powers,   designations,
preferences  and  relative,  participating,  optional or other  special  rights,
including  voting rights,  and the  qualifications,  limitations or restrictions
thereof, of each class of capital stock and of each series within any such class
and may  increase  or  decrease  the number of shares  within each such class or
series;  provided,  however,  that the board of  directors  may not decrease the
number  of shares  within a class or  series  to less than the  number of shares
within such class or series that are then issued and may not increase the number
of shares  within a series  above the total number of  authorized  shares of the
applicable class for which the powers, designations, preferences and rights have
not otherwise been set forth herein.

Article IV

         The street address of the initial  registered office of the corporation
is 1209 Orange Street,  Wilmington,  New Castle County,  Delaware 19801, and the
name of its initial  registered  agent at such address is The Corporation  Trust
Company.

Article V

         The name and address of the incorporator is as follows:

               Name                         Address

         Timothy L. LaFrey              Akin, Gump, Strauss, Hauer & Feld L.L.P.
                                        816 Congress, Suite 1900
                                        Austin, Texas  78701
Article VI

         The powers of the incorporator  shall terminate upon the filing of this
Certificate of Incorporation, and the following persons shall thereupon serve as
directors of the  Corporation  until the first annual meeting of stockholders or
until their successors are duly elected and qualified:

              Name                         Address

         Kenneth S. Shifrin   1301 Capital of Texas Highway, Suite C-300
                                 Austin, Texas  78746
         Brad A. Hummel       1301 Capital of Texas Highway, Suite C-300
                                 Austin, Texas  78746
         Cheryl Williams      1301 Capital of Texas Highway, Suite C-300
                                 Austin, Texas  78746

Article VII

         To the fullest extent  permitted by the General  Corporation Law of the
State of Delaware, as the same exists or may hereafter be amended, a director of
the Corporation  shall not be liable to the Corporation or its  stockholders for
monetary  damages  for breach of  fiduciary  duty as a  director.  Any repeal or
amendment  of this  Article VII by the  stockholders  of the  Corporation  or by
changes in applicable law shall,  to the extent  permitted by applicable law, be
prospective  only, and shall not adversely affect any limitation on the personal
liability  of any  director  of the  Corporation  at the time of such  repeal or
amendment.

Article VIII

         The Corporation  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  Corporation),  by reason of the fact that such
person is or was a director, officer, employee or agent of the Corporation or is
or was  serving  at the  request  of the  Corporation  as a  director,  officer,
partner, venturer,  proprietor,  trustee, employee, agent or similar functionary
of another Corporation,  partnership, joint venture, sole proprietorship, trust,
nonprofit  entity,  employee  benefit  plan or  other  enterprise,  against  all
judgments,  penalties (including excise and similar taxes),  fines,  settlements
and expenses (including attorneys' fees and court costs) actually and reasonably
incurred by such person 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   VIII.   The  right  to
indemnification  under this  Article  VIII  shall be a contract  right and shall
include,  with respect to directors  and  officers,  the right to be paid by the
Corporation the expenses incurred in defending any such proceeding in advance of
its disposition;  provided, however, that, if the General Corporation Law of the
State of Delaware requires,  the payment of such expenses incurred by a director
or officer in advance of the final  disposition  of a  proceeding  shall be made
only upon delivery to the Corporation of an undertaking, by or on behalf of such
director or officer,  to repay all amounts so advanced if it shall ultimately be
determined that such director or officer is not entitled to be indemnified under
this Article VIII or otherwise.  The Corporation  may, by action of its board of
directors, pay such expenses incurred by employees and agents of the Corporation
upon such terms as the board of directors deems appropriate. The indemnification
and  advancement of expenses  provided by, or granted  pursuant to, this Article
VIII shall not be deemed  exclusive  of any other right to which  those  seeking
indemnification  may be  entitled  under  any  law,  bylaw,  agreement,  vote of
stockholders or disinterested directors or otherwise,  both as to action in such
person's  official  capacity and as to action in another  capacity while holding
such office. Any repeal or amendment of this Article VIII by the stockholders of
the Corporation or by changes in applicable law shall,  to the extent  permitted
by  applicable  law,  be  prospective   only,  and  not  adversely   affect  the
indemnification  of any person who may be indemnified at the time of such repeal
or amendment.

Article IX

         No contract or other transaction  between the Corporation and any other
Corporation  and no other acts of the  Corporation  with  relation  to any other
Corporation  shall,  in the  absence  of  fraud,  in any way be  invalidated  or
otherwise affected by the fact that any one or more of the directors or officers
of the Corporation are pecuniary or otherwise interested in, or are directors or
officers of, such other Corporation.  Any director or officer of the Corporation
individually, or any firm or association of which any director or officer may be
a member,  may be a party to, or may be pecuniarily or otherwise  interested in,
any contract or transaction of the Corporation, provided that the fact that such
person  individually  or as a member of such firm or association is such a party
or is so interested  shall be disclosed or shall have been known to the board of
directors  or a  majority  of such  members  thereof  as shall be present at any
meeting of the board of  directors  at which  action  upon any such  contract or
transaction  shall be taken;  and any director of the  Corporation who is also a
director  or  officer  of such  other  Corporation  or who is such a party or so
interested  may be  counted  in  determining  the  existence  of a quorum at any
meeting of the board of directors  during which any such contract or transaction
shall be  authorized  and may vote  thereat to  authorize  any such  contract or
transaction,  with like  force  and  effect  as if such  person  were not such a
director or officer of such other Corporation or not so interested. Any director
of the Corporation may vote upon any contract or any other  transaction  between
the Corporation and any subsidiary or affiliated  corporation  without regard to
the fact that such  person is also a director or officer of such  subsidiary  or
affiliated corporation.

         Any contract, transaction or act of the Corporation or of the directors
that  shall  be  ratified  at any  annual  meeting  of the  stockholders  of the
Corporation,  or at any special meeting of the  stockholders of the corporation,
or at any special meeting called for such purpose,  shall,  insofar as permitted
by law, be as valid and as binding as though  ratified by every  stockholder  of
the  Corporation;  provided,  however,  that any failure of the  stockholders to
approve or ratify any such contract,  transaction or act, when and if submitted,
shall  not  be  deemed  in  any  way to  invalidate  the  same  or  deprive  the
Corporation,  its  directors,  officers or  employees,  of its or their right to
proceed with such contract, transaction or act.

         Subject  to any  express  agreement  that may  from  time to time be in
effect, any stockholder, director or officer of the Corporation may carry on and
conduct in such person's own right and for such  person's own personal  account,
or as a partner in any partnership, or as a joint venturer in any joint venture,
or  as  an  officer,  director  or  stockholder  of  any  Corporation,  or  as a
participant  in any syndicate,  pool,  trust or  association,  any business that
competes  with the  business  of the  Corporation  and shall be free in all such
capacities to make  investments in any kind of property in which the Corporation
may make investments.

Article X

         Election of directors  need not be by written  ballot.  Any director or
the entire  board of directors  may be removed,  with or without  cause,  by the
holders of a majority  of the shares  then  entitled  to vote at an  election of
directors,  except as  otherwise  provided  by law.  In  furtherance  and not in
limitation  of the powers  conferred  by statute,  the board of directors of the
Corporation  is  expressly  authorized  to  adopt  the  original  bylaws  of the
Corporation,  to amend or repeal the bylaws or to adopt new  bylaws,  subject to
any limitations that may be contained in such bylaws.

                            [Signature page follows]


<PAGE>


S-1

043838.0012  AUSTIN 151829 v2

                                 SIGNATURE PAGE

                                       TO

                          CERTIFICATE OF INCORPORATION

         IN WITNESS  WHEREOF,  the  incorporator of the  Corporation  hereto has
caused this  Certificate of  Incorporation to be duly executed as of January 14,
2000.

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                                 Timothy L. LaFrey, Incorporator