dynamat is the best out there, that i have found so far anyway. my car is full of dynamat extreme. if your trying to kill road noise, the best spot i have found to cover was around your rear speakers, try going to wal mart and buying some of that poly fill stuff (like 2 dollars a bag) buy about 6 bags of it, cram the holes back there full of it, then throw on a layer of dynamat extreme. hope that helps.
Brandon