6 ¾". Standard 6½" speakers can be made to fit by drilling the mounting ring, but it would be best if purchasing new speakers, to buy ones that already have an adapter ring included or are already designed to fit 6¾".
Also, because the speakers are mounted low in the door, choosing ones with a pivoting tweeter would be wise.
The rear speakers are the same size of the front. 6.75" but 6.5" will work also
they are 6x9 speakers and hard to get out
5.25
The front speakers are 4" and the rear speakers are 6 1/2".
they are 5x7 front and rear. try infinity kappa speakers in this size
Front and rear speakers are 6 X 8.
Crutchfield.com says that the front speakers are 6x8, and the rear speakers are 6x9.
6 x 8
The rear deck speakers are 6x9s
6.5 Speakers both in-front and rear
6.5S 6.5S
Not sure what size the tweeters are, but the mid range speakers in both the front, and rear doors are 6.5"