I have these PPI 4" speakers sitting here, nice pieces. 20 bucks brand new. I know CS holds a 5 1/4" speaker, but has anyone ever done a 4"?? My current setup is stock 3.5s, stock 5 1/4s, and Boston Rally 6x9s in the rear. I am running a Rockford Fosgate MP3 deck which runs the stock speakers in the dash and CS door panels. My 6x9s are run by a RF Punch 40x2. In the trunk is 3 RF DVC 10s and a RF Punch 200x2. It sounds pretty decent the way it is now, but Id like to be able to replace those front speakers with better quality than stock. But, it is not a priority for me to go out and buy new speakers, as I have other things that need attention on the car. (READ: Transmission). But I would like to possibly take advantage of these 4" speakers. I wouldnt be cutting anything up, so if one day I wanted to buy some 5 1/4ths, that wouldnt be a problem putting them back. Any input would be appreciated. Thanks