There is indeed a company renting Westfalias in Maui:
http://www.imua-tour.com/

You can find a diagram of the layout on their website.
(click on the "i" button in the westfalia description
text)

Maui has some very nice campgrounds in the national park,
both on the top of the volcano and by the seaside. I'm not
sure if vehicle camping is technically allowed there though.
We tent camped when I visited.

Best,
Martin

   Delivered-To: jag@cs.yale.edu
   From:        Eltonh1011@aol.com
   Date:        Thu, 24 Jul 2003 15:45:20 EDT
   MIME-Version: 1.0
   Content-Type: text/plain; charset="US-ASCII"
   Content-Transfer-Encoding: 7bit
   X-Mailer: AOL 5.0 for Mac sub 28
   X-Envelope-To: <jag@cs.ualberta.ca> (uid 60001)
   X-Orcpt: rfc822;jag@cs.ualberta.ca

   2003-jul24   Ithaca NY

   Hi, Martin-

   I came across your website looking for a diagram of the Westfalia camping
   layout. You ought to have one on your site. (If you have one, I didn't see it.)
   Didn't know they made a diesel model of the Westfalia. Our daughter has a
   diesel Jetta and likes it very much.

   My wife and I are planning a camping trip to the islands of Maui and Hawaii
   in January. When I came across a reference to the Westfalia today, it struck me
   this might be much more convenient than a tent (we are both in our 70's). I'd
   appreciate your thoughts.

   Elton R Homan, PhD
   Visiting Fellow
   Cornell University
   eltonh1011@aol.com

   (U of R Sch Med and Dent 1958-62)