I have a couple of cans of rubberized undercoating sitting in the garage; I'm gonna do the exact same thing, just waiting for it to warm up outside (darn Canadian winter won't go away) or for my brother to get his bronco out of the garage. I don't know exactly how much noise it'll block - doing the firewall and hood would probably help a lot - but I hope it'll insulate a little in winter, too. It gets darn cold up here in Manitoba and I don't have any carpet and my Herculiner isn't in yet, either.