[Aryding]

I'm planning on putting Infinity Kappa 6x9's into my car. First, is there enough clearance to cut and modify a hole in the doors to accept these speakers. Second the rear deck, how thick is it, because I was thinking of putting a piece of MDF board in place of it and mount the speakers in my own specified holes...

[lcurle]

no 6x9s will not fit up front unless you seriously modify the front bracket and the rear deck. Easiest way to do the rear would be to cut out the metal and bolt in some particle board with the 6x9 holes precut for easier mounting. The front would need an entire custom mount to accept 6x9's.

[Blind_Guardian]

If i were you i wouldnt put 6x9s in the front or back, Mostly the front though.
Round speakers give better sound quality and if you bought infinity i am guessing that is what your going for. For the front get an infinity component set and just get the speakers that fit and mount the tweeter close to it. I have Infinity Refrence series component speakers and they sound great. Well they arent hooked up any more... Damn poeple breaking into my car.(Meh atleast i still have em) As for the back You can do the oval speakers it doesnt make a huge difference. IMO you dont even need back speakers for quality.

-Guardian