I have found a way to improve the function of the AC in my '88 W'falia.  I
purchased a 12V fan from W.W.Grainger p/n 4C586.  This is a high quality 6"
fan that you might see on a school bus, etc. ( A $10 cheapo might work as
well)  I mounted its pedestal base to a piece of 1/4" sintra (polystyrene)
but 1/4" plywood or masonite would do as well.  This assembly slips between
the mattresses of the folded upper bunk with the fan hanging upside-down in
front of the AC outlets.  For wiring, I mounted a SPDT switch on the box
under the rear seat which houses the rear heater core & blower.  The red wire
to the blower motor (after the series resistance) was redirected to the
center contact of the switch.  The other two switch contacts are to the rear
seat blower and the fan.(I also picked up a ground for the fan at the rear
seat blower)  At this point it is just a matter of discretely snaking the
wire up to the fan. With this setup, the fan leaves no permanent scars, and
can be controlled by the three speed switch for the rear seat heater.  This
fan, even on low, brings lots of cool air forward and makes the AC work "like
a real car ".    G.