Rubber Carpet Replacement

Anyone use a raw/universal material for rubber carpeting? I've heard the vehicle specific ones are crap. My floor is currently herculined and heat insulated underneath and am looking to do more sound deadening. Dads 04 work truck has factory stuff and its nice and quiet. Haven't pulled it up to see whats underneath though. Never installed carpet but have heard its tough to form the shape of the floor.

I highly recommend Don Sambrook's system for sound deadening. He's the only guy I've ever found who has put some serious effort into truly researching what works and what is just "snake oil." He started out as just a guy who compared products but became more scientific as time went on and eventually started his own service. His website, http://www.sounddeadenershowdown.com, has a lot of great info, and if you poke around the web a little, you can still find some of his older info and evaluations.

I know all that doesn't directly address your question, but going the above route would mean that you would no longer have to consider a carpet's limited sound deadening potential when choosing one.