A friend of mine is giving me a cat-back GReddy exhaust for FREE in swap for my stock CRX Si exhaust. Pretty cool, huh? It's in great condition. But...

It's got a silencer on it, so it's not super loud, but I'd still like to make the cabin a little quieter. Anyone got experience putting down Dynamat? I wanna put a layer in the trunk, and possibly some under the carpet. How much work it is? thanks