Vinyl based sound deadening?

I am on the search for an economical solution for sound deadening my car, for the purposes both for the typical audio reasons and becuase I hate road noise, stereo on or off. While looking around I found this vinyl material. Its about $20 per 12 sq ft, not too bad, hard to find better Ive found. I am trying to stay away from peel n seal and its similar asphault products. Yeah, I know lots of people have had sucess, but I also do a lot of traveling, and I know how it will respond to Phoenix summers, so its a no go. Anyone have any experience with this product?

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=268-020

Thanks all!