i have heard different things about what speaker sizes come stock i hear the speakers in the front door are smaller then the ones in the two little back doors anyone have an '04 and know for sure?

 

According to crutchfield.com The rears are also 6x8/5x7

My tip to you is NOT to replace the rear speakers. Get a good set of speakers for the front and fade your radio forward. The rear speakers contribute very little to the sound quality, unless you're just going for loud.