Pull the panel and measure. Good luck.

 

f those rear panels are a pain to pull. i got a sub box that squeezes in on the bench in the back so getting it out is going to be a pain to put my speaks in. yea myne are 6x9 in the front and 5.25 in the back. all alpine

 

In my 01 I had 6x9's up front and I don't know if it was 5.25's or 6.5's in the rear. Anyways I used an adapter bracket and put 6.5" Polk DB's up front. After a few months I decided to go with components. I put my Polk Components I got up front and moved my 6.5" Polk DB's to the rear. They fit perfect in the factoryspot with no modification. They look slightly larger than the factory speakers not sure if they are or not but they fit great.