How much modification would be needed to fit a 8 inch jl audio w3 with a mounting depth of 4.03 inches. What depth are people running with 6 1/2's. With my Boston Acoustics Pro's in front I had to make a 3/4 spacer. I am guessing since the window doesn't go down all the way I got more room.

 

4 inches is DEEP for doors...I would try to get something with a lower profile.
Standard MDF ring org members are using is 3/4"

 

WAY too much for what its worth, especially considering youll need to Completely seal em.

 

just stick with a 6.5 mid bass.