[ShagginJet]

Lets see if i can help. Up front, the car can handle a shallow 6.5 speaker, or you can use the outter grips on a 5-1/4 and get it to fit. Regardless you should be able to get a 6.5 in there if you want. As for the rear, it's most likely a 6.5.

The head unit: The head unit should be a little small when compared with the space. The unit should have a aluminum bracket that pops into the factory hole. Then you bend some tabs out to hold it in place, then the head unit pops right into the bracket. You may need to use a sharp tool to make the dash hole just a tid bit larger.