I think the affect of the butyl dampener on actual internal vehicle noise is minimal. I've done that part, and my doors close thunkily now (not that I ever care

I think the affect of the butyl dampener on actual internal vehicle noise is minimal. I've done that part, and my doors close thunkily now (not that I ever cared) but the car is just as loud as ever inside. I think that unless you're going for high-performance audio, there's really not a whole lot of value in the sound deadener. > 25-50% coverage with butyl directly on the sheet metal is enough This is true, you see in a lot of the professional installer videos that they will cover the whole surface in the deadener, but it's not necessary.