What have you guys used as sound deadener? dyna mat is expensive. Eastwood has there brand which is cheaper. some guys have used a foil and tar based roof material from Lowes or home depot but i'm wondering if my car will smell like tar. and some guys have used a rolled foil insulation from Lowes thats for the home that they have glues down. if you have used the eastwood stuff how many boxes do i need? each box does 33 sq ft.