Hi there, If you search this has come up quite a lot, I've just partially done this so can tell you what I have done, no promises its any good but its a start.
I spent some time reading the various comments and in the end decided to only go with a very limited amount of sound deadening and insulation for 2 reasons.
1. The noise levels in my bus never bothered me enough to be worried about making it silent, its not a Rolls Royce
2. Its a drafty van with lots of glass and over half the roof has been replaced with a fibreglass top.
I read that you only need sound deadening on about 25% of a panel and the deadening material (think its Butyl based, might be wrong) is flippin' heavy so I'm not going to cover the entire bus.
There is a company that sell stuff on Ebay, I spoke to them and they were helpful. I bought a pack of Silent coat which is self adhesive sound deadening and a pack of the closed cell foam self adhesive sheets as well. I have used the silent coat to cover at least 25% of the front of the cab roof, doors, slider, hatch, side panel, front panel and the rear air intake channels (not sure what to call this but the back of the bus where you will get engine noise from) On the cab roof I have covered the front with the foam and the rear intake channels as well, I also bought a specific engine bay sound proofing and heat barrier from the same guys.
You can see some of this at the end of my build thread here (scroll down):
http://forum.earlybay.com/viewtopic.php?f=2&t=23320&start=100" onclick="window.open(this.href);return false;
I've also make sure I have covers/seal for all holes that draughts come through, pedals etc and my heater tube is well insulated so that heat actually gets to the cab area.
I have seen some people go to town with insulation but with the amount of glass etc I didn't want to do this.
Hope it helps.
Mags
