It goes thud.....Thats what you want. Havent used Genuine Dynamat but my busted ears can pick the difference and Wifey has commented on the reduced road noise so it must be doing something. I have covered the boot floor and boot lid and selected interior panels (back of glove box,Shift console, roof console etc gets rid of plastic rattle) and probably have 4 or 5 sheets left from two boxes. I think I'll need a third box to completely cover the front and rear doors. Tocchi uses a "happy tiger" brand from Volatile Car Audio in Malaga and has has similar positive results.