I've done a series of things that have resulted in a much more quiet Westy. 
I'd like to describe my experience and ask whether one modification will cause 
problems. 

First, I had a persistent and mysterious hollow knocking coming from the 
cabin area.�  I took the van to a larger garage that specializes in tires. The 
mechanic had me drive while he rode in the cabin and thoroughly looked for the 
source of the sound, at least the general location. Initially, he was also 
mystified. 

To demonstrate the sound, I stood on the rear bumber and rocked the van hard 
-- up and down. What we heard was a nearby steel on steel high pitched clang. 
The source turned out to be very simple -- loose bottom nuts on both shock 
absorbers. He tightened the nuts and sent me on my way with no charge. Not bad. A 
substantial reduction in noise for no charge.

The second noise challge was more obvious, more common and more difficult: 
wind and road noise at highway speed. In my Westy, we can still carry on a 
conversation at 70mph but it becomes difficult. I initially planned to buy rooled 
roofing tar to place in the doors and floor but was disullisoned when I saw it. 
Too stiff and it seemed to have little potential for sound management despite 
what I had read in the Archives. I rejected the several commercial options I 
had seen on the net as too expensive. Finally I found a product at Manards 
that is easy to work with, cheap, and it works. It's "Reflectix." 

Reflectix is described at its web site http://www.reflectixinc.com/rv.asp� as 
follows. 
"Reflectix� is a 5/16" thick, seven layer, reflective insulation which is 
available in rolls of various widths and lengths. Two outer layers of aluminum 
foil reflect 97% of radiant heat. Each layer of foil is bonded to a tough layer 
of polyethylene for strength. Two inner layers of insulating bubble pack 
resist conductive heat flow while a center layer of polyethylene gives Reflectix� 
high reliability and strength" 

I installed the relectix to the inside of both front doors and to the fire 
wall. I also installed it under the black rubber cabin floor. I do not use 
carpet in my cabin, prefering a simple rubber cover that is easily removed for 
cleaning. I used a bit of carpet tape to stabilize the reflectix.� Walking on this 
floor seems not to injure this insulation. The inner polyeurethan bubbles do 
not pop. I also installed this barrier over the entire engine compartment. I 
did not tape it down or use other adnesives in this area because I am unsure 
whether it's good to use this product over the engine 

My sliding door and rear hatch are already full of fibre glass insulation,� 
thanks PO. I left them alone. A� test drive on the highway reveals a much 
quieter van. I estimate a 50% reduction, perhaps more!.

My right door installation was my first try with this product and I used an 
aggressive spray adhession product. I worked so great I wished I'd hadn't used 
it. If I have to do repairs inside the door, I will have to remove this stuff 
first. Not good. So, On the drivers side I used  standby duct tape to cover 
the entire outside edge. Cleaner, lighter and works just as well.

So it looks like I have quieted my van for about $50 and I overbought the 
amount of rolled reflectix. Is this sound dampener/heat insulation product going 
to cause any problems, especially over the engine? Is someone going to ruin my 
day or congratulate my progress.

Comments appreciated.