So I've got an '89 Isuzu Trooper and I'm thinking one of the things I might do to deaden the interior is spray Great Stuff in the door panels. I would be super careful and only use a little at a time since I've heard about how it can push on the metal. Keeping in mind that I'm on a super tight budget, I've got two questions:
1) is using Great Stuff actually a legitimate thing to do or is it a dumb idea that got spread around like Peel and Seal?
2) this SUV has the dumbest speaker setup ever (2 speakers in the kick panel and 1 on the back hatch) so I want to add at least 1 speaker to each of the doors. How would I put it in if I need space up top to roll the window down and space down below for speakers? Would I just put a little in the middle of the panel or put it everywhere and just cut out what's in the way?