I have an 02 WRX that has dogshit for a stock stereo, so I am looking to upgrade. I have a Rockford Fosgate punch 360a 2 channel amp that used to power 2 12" subs in my Lincoln. I still have one of the subs, but not sure if it is needed in the smaller subaru cabin. It uses 6.5" speakers in the door, and also a seperate tweeter location, in the rear it uses 2 4" speakers. All of these components sound terrible and must be replaced. THe question is should I(can I?) use my amp to power the speakers and a single sub, or would it be better to just let the component speakers handle all of the audio? Also what should my budget look like for a project like this to get a decent set up?