Speaker sizes ???

If you had Bose system they should be 6 1/2 inch and have amp attached so may have to adapt with alternate collar or kit. This is the size i have infront and back.

i have a 2001 maxima and i have custom speakers everywhere. in the 2001 the front door speakers are 6.5 and the rear doors are 5.4. the rear dash had a 8 inch sub. my car came with the bose stereo which i removed