there is a thread in the audio forum that covers all this...and by our resident EXPERT.....
the fronts are in reality 5X7's....however a 6X8 will go in there as well. its the back spacing you have to watch out for your your window will contant it when you roll it down.
the rears are in fact 6's....although most all 6 1/2's fit the same hole...the backspacing isn't a factor in the rear doors....and the rear speakers are odd in the fact that they only have three mounting screws and all aftermarket speakers have 4.
NOW, this thread will apear in the proper forum... (stash)