sound killer

Umm, it is more complicated than you think, pm me and i'll give you a link to another forum's discussion. It was between me and them they know a lot and help greatly.
It depends what your goals are, and how much you are willing to pay.
Rough estimates,
Eliminating basic engine and road noise will set you bak around 150ish
Making your car sound as quiet as a bmw or a benz goes to 650 to 1k
 
its easier to just focus on making the good sounds louder, LOL.

On a side note, I picked up some stuff called "peal and seal" from Lowe's, its some sort of self adhesive heavy rubber with a aluminum foil type backing on it, pretty much like Dynamat or whatever, but 90% cheaper, I put it on the roof and inside the doors of my 65 F100, and it helped a bunch. I think the stuff was originally made as a gutter liner, or to patch metal roofs of something. Don't think for a second that Dynamat, for all the hype, is a 'new' special product for sound deadening.
 
they have something very similar at some carpet and foam places. i got some for my first car that was a foil lined enduralator..... like particle board (but carpet) and it was very very very cheap and worked well.........
matt
 
Because some forums get mad when you post links to other forums, but if it doesn't matter I suggest going over to secondskinaudio.com, their forums are dedicated to only sound deadner, the forum you want to look at is the product selection section, my own thread is there and so is bad68coupes.

Just relaying info, they don't suggest using peel and seal becuase it has poor adhesion qualities.
 
3 years so far for my 'peel and seal" in Georgia heat and humidity. I don't think I could take it off if I tried. My prep consisted of spraying the surface with windex and drying it with a paper towel.