Thanks for all the great ideas on how to quiet my bus.  I thinking 
about using regular insulation material in the walls as it would not
only deaden the sound but insulate as well.  I like the idea of 
spraying the undercoating on the inside walls...also adds a layer of
protection against rust/moisture. The sound deadening material sold
through VW Trends...I have to look into that..no one has used it I take it
well..someone has to be first..
Encasing the back engine area with plywood is a good idea...I know when 
I had a sheet of plywood lying over the bed the noise dropped...

None of you has mentioned anything about any special rubber transmission
mounts.  

Carpeting, a good commercial grade with a tight weave might work...I don't 
want any dirt gathering inside.  And a heavy fabric for curtains will add
some sound deadening.

Any other ideas?   

Martin           '71 Bus