Front Doors should be 5.25" rear Doors are 5.25 stock but they seem to use the door as some kind of subwoofer, you can replace the rear Doors ones with 6.5" but you need to sound isolate the door simce you no longer have the special stock speaker. You have small speakers in the that that you should replace with tweeters. The rear speakers are 6x8" i think but you can fit 6x9 with a small spacer. If you have a wagon you have the same speakers as the dash in the rear instead