A few items on quieting down vanagons:

My 90 Carat developed a wind whistle somewhere over the passenger door.
The solution ended up being to armorall the tubular rubber seal and
clean and wax the mating surface on the door jamb. This is the same
thing I did to stop the water leak on the rear seal of my westy--it's
easy to get leaves and trash under the back hatch seal and not know
about it.

I notice a noisy leak when my airflow lever is turned to "off" position
which is a misnomer because it isn't off, it's leaking. But when I open
it all the way the noise disappears, too, meaning that air is whistling
in around the breaks in the deteriorated foam rubber seals in the
heater box, and they need to be replaced.

On my (notoriously noisy) diesel westy, I wanted a cheap,
easy-to-implement sound deadener. I went to a local discount surplus
store and bought two big, thick rubber industrial mats, the kind a
machine operator might stand on, tough enough to resist oil and metal
shavings. It has a thick, tough rubber hide bound to a dense, cushiony
foam. A piece about 4 x 5 feet was eight dollars, so I bought two. I
fitted one to the westy rear cabin so it can be removed like the
original carpet piece under the mattress. the other piece butts up
against it and runs down the interior of the firewall (with neat
cutouts for the seal belt attachments), over the floor, and up the
inside of the wooden kickboard on the face under the seat. I used
carpet tape to secure this second piece where it butts the engine cover
piece.

After reading the posts of the last few days, it makes me want to get
another pice of that material and try the front.

You could never make one of these things totally quiet, but it was
cheap and it helps. I don't know what it would be like in my 2.1 Carat,
it's not noisy enough to go to the trouble. I have pictures if anyone
requests them.

One last comment: For a while after I got the westy, I had to put up
with a noise on decelleration (like to a stop light from 65 mph) that
sounded like either part of the exhaust system or maybe the timing belt
cover was drumming on the body somewhere. It was really loud. I changed
my rear tires to light truck tires and the handling improved, but
didn't want to commit to all four tires until I knew I liked them. I
did like the tires, so a month later I replaced the front tires too.
Guess what... the sound went away! Go figure.

Jim