I used the foil-backed roof stuff in the front doors after running out of the brand name product.  Instant availability and reduced price, about 30% less as I recall,  made it worth a try and the result seems identical.  

Stephen

--- On Sun, 4/29/12, Jim Felder <jim.felder@GMAIL.COM> wrote:

From: Jim Felder <jim.felder@GMAIL.COM>
Subject: Question about sound-deadening alternatives
To: vanagon@GERRY.VANAGON.COM
Date: Sunday, April 29, 2012, 6:51 PM

Alternative for lack of a better word—meaning an alternative to the
expensive products made for the purpose, that I have to order and
can't get more of if I run out.

Over the years I have heard people refer to a peel and stick
asphalt-based product they got at the home stores. I was poking around
today and found various sizes of rolls of peel and stick flashing. I
was not impressed with how thin it was.

Is this what people are using? Is there another product I should be
looking for? Is it just not worth it, and I should be ordering the
real deal?

Those with opinions, please share.

Jim