If you are thinking of moving the 6x9s into the side wells of the rear plastic DONT.
6x9s blow nuts.
If you want to do this get some decent 5.25" or 6.5" Mids. There IS room.
Simply cut a hole
accurately with a jig saw, dremel tool or butter knife. Then use the included grille covers. Or get some grilles if yours didnt come with any.
http://caraudiocentral.net/ryan/docs/Learn_rearfill.pdf
http://s38.photobucket.com/albums/e1...t=100_0336.jpg