Reading Topic: speaker size?
Yes, no, and yes.
I have three pairs of brackets in the mail for this purpose. I bought them off of eBay- they were hard to find. Unfortunately, they aren't here yet- I paid for them two weeks ago! I have 5 1/4" components that are going up front- smaller, rounder drivers will give a smoother midrange, but smaller drivers typically have less low-end. Then again, the largest drivers (6"x8" components) are hard to come by.
Consequently, since I have a subwoofer now, I may be selling 6x8" Kenwood components which have yet to be installed. I might put coaxial speakers in the back instead.