I noticed that the driver & front passenger doors have a pretty large speaker housing. Would it be possible to fit maybe (2) 4 - 5" coaxials / seperates in there??

Yes I have a 4" and a 6.5" in the doors

Cool, were they coaxials or seperates? What did you do for the rear speaker housings?

have any pics?? how modified is the rest of your stereo setup?