not shure if its the same as a 05 but you can get on crutchfield.com and go to out fit your ride and it will tell you, if they are the same its 6x9's in the front door and 6 3/4 in the rear and they dont make anything to replace the dash speakers
yep 6.5 in in the reap and 6x9 in the front door. I put 6.5 in in both front and rear doors. had to make a bracket so they would fit good. I used a piece of 3/4 in MDF to make the brackets to adapt the 6.5 to the factory location and mounting points
for a few reasons. first I allready had 2 sets of jl audio zr 6.5's from my frontier.
Also I think that you can get alot better quality speaker in a 6.5 vs. a 6x9.