sound deadening

[hgupta]

Last night I ripped out all the old carpet and horsehair pads off the floor of my '57 190SL to repair rust holes. I want to deaden roadnoise as much as possible since I am putting in a nice sound system. I sprayed down some rubberize undercoat (prevents rust and deadens some sound) and put down a layer of dynamat like stuff. Is that sufficient, or should I also replace the horse hair?
The replacement carpet is really cheap and has no backing. Should I just lay it down on top of the dynamat, or is there a carpet backing available that also deadens noise? Any other suggestions before I lay the carpet down?

[Mattk]

Dynamat and spray undercoating will deaden sound a little but is mostly used to eliminate vibration. I would liike for a car carpet backing if possible.