I think if you will get a vacuum storage canister (you remember those funky
black plastic bunch o'balls under the hoods of old vw's, the watercooled
ones) it would remedy your problem.  I once fixed a Saab (swedish vanagon at
heart) by replacing a storage canister.  The lady would hit the gas and the
drop in manifold pressure would switch the a/c into defrost mode (default for
most Euro cars), real nice in the middle of a richmond summer!!  Just place a
"T" in the line to the front and add a vw or similar canister!
Patrick F.  and screamin'baby thomas

 Does anyone know of a way to make this better?  I also have a Volvo 740 into
which I put the same kind of cruise control from an Audi and it
always stays right on the set speed without varying. >>