If your gonna spend money on your car, stereo, anything. Why do a half assed job?
The stock plastic pods, rip em out and burn them, they're shit for sound quality.
Make up an MDF spacer to perfect size for the speaker your installing, you have alot of room behind the speaker before it will hit the window. I have Rockford Fosgate X162S splits (awesome splits) and they fit with miles of room to spare. I really recommend dynmatting your doors if you can afford it aswell, well worth the money!!!