ive heard of people using this peel n seal self-stick aluminum faced gutter patch stuff. you can find it at HD in 6"x25' for ~$15. i checked it out the other day while i was picking some stuff up. it seems pretty thin so maybe double up on layers.
might have to watch out for the smell though....might stink up...if your car is in the sun all day...or even worst...melt!.....test it out though...let us know if it works....peace 0
I think it was jman who was saying that that stuff is actually really good and doesnt smell at all, well as good as it gets for 15 dollars, good for doin large areas but important things like the door should get better grade sound dampening.