I have one of the Behr units in mid installation...to mate up with my
factory rear unit....but....

I called the guy from European Cooler, his name is Jerry West.  His shop is
near Dallas, Texas.

http://www.europeancoolerair.com/ftrmkt01.htm

Sounds very knowledgeable and has a custom designed kit for front air in a
Vanagon that sounds to me like it has advantages over the Behr unit.

1.  Evaporator is more efficeint - 16,000BTU's vs 12,000 for the Behr.

2.  Unit is smaller and (HERE'S THE BIG ONE) ....it doesn't require removal
of the dashboard to install it.   Take it from me.....that's a BIG DEAL!  I
did it and it's a major PITA.

3.  You don't lose half your glove box as you do with the Behr.

4.  He sells a custom made center vent that fits on top of the dashboard
above the ash tray hole so that you get to keep your radio in its normal
location.  Also a BIG DEAL!.

Kit parts to mate a front blowing system into your existing factory rear
unit are about $700.

Whole kit if your van has no factory air is about $1800.

Very friendly ....very knowledgeable guy.   If I didn't have my Behr unit
90% in, I think I would go with his system instead.

My 2 cents.

Warren Chapman