Ya, I have read before that people have done that. The plexi glass piece to fill the void is called a baffle (IIRC) The ones I have read are made of 1/2 to 3/4 inch MDF. So if anyone has done this and is reading is 6" as big as you can go??
98.5 Black SVT with 34k miles Build #5683 Born on 4\15\1998
WR Headers GMK CAI
Blaupunkt system fiberglass tweeter pods
L.E.D. tail lights in the works
