I had a good experience with McDonald VW in my town of Littleton, Colorado.

I asked them to troubleshoot a cold idle problem on a 90 Westy that several
list suggestions didn't help, and a couple previous mechanics couldn't
figure out.  I went there thinking they would be able to do some diagnostics
using VW specific equipment that maybe only a dealer would have.  They
actually couldn't figure it out but they stuck by their quote of $175 to
diagnose the problem.  After a couple days, they called a retired tech in to
have a look.  A couple days later they gave up and my cost was still only
cost $175.  They probably had at least 15 hours in it.  I thought that was
pretty good.  Prior mechanics just convinced me to throw parts at it.

Epilogue:  Eventually I did just throw parts at it, but they were used parts
that I put in myself.

>From: John Reddick <SVYOLO@YAHOO.COM>
>Reply-To: John Reddick <SVYOLO@YAHOO.COM>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: VW/AUDI Dealer Reviews
>Date: Wed, 21 Dec 2005 22:22:36 -0500
>
>Horrific. all of them.  Maybe somebody here knows a good one so please let
>the list know.  If VW didn't build cars people really wanted, the
>stealership network here in the US would scare them off.