When I installed the fold-up table salvaged from a Carat (thanks Sorin!),
into my '89 GL, I chose to keep my old Weekender back bench seat/bed
(actually, I only found out about the width interference after having
installed the entire plastic panel assembly - d'oh! - and I was too
pissed off to spend any more $$ on the project.)

To accomodate the original Weekender back bench seat, I had to do 2
things:

1) Got rid of the plastic panel assembly - this is where the back seat
first interferes.  Instead, I made a cutout in my original
pressboard/vinyl paneling into which the table is more or less recessed
when folded down.  Paneling now bulges out just a bit.

2) Cheated the table forward about 5 inches or so (can't remember the
exact distance) so that the back seat doesn't interfere when folding down
into "bed mode".  This involved remounting the table folding mechanism
farther forward on the steel frame that comes with it and supports it.
This was actually much easier than the prissy cosmetic operation I
performed on the panel.

As a result the table is somewhat distant from the back seat when both
are folded up; however, it's a PERFECT distance away when the seat is in
"bed mode", which is how I usually leave it when camping.  Also, I don't
have the Carat jump seat installed - I'm usually bringing along too much
crap to give over precious floor space to another seat.  Instead, I
mounted the driver's seat on a standard Westy swivel, and when turned
around 180 degrees it's just the right distance from the table.

My girlfriend and I have eaten many a camp meal this way during inclement
weather: her on the bed and me in the driver's seat, which I believe is
the proper seating arrangement ;-) for a Vanagon couple...

-Steve