Do you have a plain GL or a Wolfsburg edition (also GL)?  I don't know
about the plain ones, but in the Wolfsburg's, the backseat lays out to
form the remainder of the queen size bed (with that mattress over the
engine compartment being a portion of it). 

The area under the seat back there can be used for storage (that's where
my curtains stay) and it is also the location of the ECU(brain).  Thus,
you would need to lift the seat up to access it if you should ever need
to test it.  Warning concerning storage, don't put anything metal on the
half with the ECU.  There has been a report from one owner that a
toolbox managed to ground out the ecu occasionally and cause power
problems.  When he moved the toolbox, no more problems.

Check the archives concerning the vents.  About a month ago there were a
couple postings of remedies (involved removing front grill and blocking
the air intakes somehow as I recall).

Tonya
87 Vanagon GL Wolfs
74 S. Beetle