I really think that you will be sorry about getting a different van than a
Vanagon.  Most domestic and Japanese mini-vans are basically taller station
wagons with no real room (like a Vanagon).

I went to the Philly car show last year and tried out all the new minivans to
see how they stacked up to the Vanagon.  Most of them were very cramped
inside (especially that new Toyota minivan.  Man they designed this thing for
migits or something.  Really no leg or head room for a 6 foot tall person
like me.)  So if you want more room than your TDI wagon I would not look to
the mainstream.  The only two minivans that I can think of that are similar
in room to the Vanagon are the Eurovan and the Chevy Astro van.

As far as noise goes, what do you have a aircooled Vanagon or something?  I
have found the watercooled Vanagons with good exhaust systems to be very
quiet.  If yours is watercooled and noisy then maybe you have a exhaust
system problem or an engine problem.  My Carat floats down the road with very
little engine noise and road noise.  A VERY comfortable van that rides very
well, and handles well (throw both of these away if you go with a domestic
van).  Its also nicer to have the engine in the rear as this moves the
vibrations of the engine and heat to where you aren't sitting (under the back
deck instead of right at your feet).

My 2 cents on this one.  I would tell you which minivan that you should run
away from but I would probably be sued by the Chrysler corporation so I won't
mention it. :)
Next time you are bored count how many Car*vans are emitting blue smoke from
thier tailpipes.  You will be surprized to find that it is almost all of them
(at least the ones that are more than a couple years old)!
Ken Wilford
Van-Again
John 3:16