Well, I used to have the same problem in my 93 xlt. What I did to fix it was removed the door panels, and removed the black material between the speaker and the cage on the door panel. this seemed to have worked well except there is still stuff in the bottom of the door panels in the rear.
What do you guys think? That material didnt serve a purpose did it?
What do you guys think? That material didnt serve a purpose did it?