The system consists of a Sony CDX-C780 Head Unit that I installed. It's not a very special unit, in fact the shop that installed the rest of the system tried to talk me into another head unit, but I kept it since I like the steering column remote (I can control everything without looking down from the road) and the fact that I have the same unit in my daily driver, a 2000 Toyota Tacoma TRD Prerunner. Bottom line, the head unit has a good output for the rest of the system. The speakers for the system consist of MB Quart 1" tweeters in the stock location. 6.5" MB Quart Mids in the stock location (the doors are sealed with sprayed on sound deadening material inside and the addition of Dynamat. The doors also house the crossovers for the tweeters and mids. Since my car is a hardtop and I don't have to worry about T-Top storage the subs are two JL 10", one behind each seat. We removed the cover of each storage area behind the seats and the custom made vinyl covered MDF boxes actually use that area as part of their .65 cubic feet. Power comes from a 500 watt Phoenix Gold 4 channel amp located under the drivers seat. Since the amp has a three speed fan, cooling in that location is not a problem. One other thing to consider, I have Recaro SRD seats in the car. The seating position is not any higher than stock, but I don't know if having those seats enabled the location of the amp under the driver's seat as compared to the stock seats. I did retain the stock 2.5" speakers behind each seat for a little fill and they are powered by the head units 40 watts per channel. All in all I'm very pleased with the system and I've received nothing but positive feed back. I have also been encouraged to enter it in competition in the amateur category. We'll see. Radar White 95NA Hardtop