The main speaker set up is a component set by CDT Audio - if you haven't heard of them, its truly awesome stuff. CDT makes a component set called "up-front stage" sound that incorporates 4 tweeters at the front of the car, a left and right set for both the driver and passenger, and 2 mids (in the front doors). The crossovers are engineered to provide a split to each side like this: L Mid, L Twt, L twt and R Mid, R Twt, R Twt. Then in the rear doors I have another set of 6.5" mids (no additional tweeters aside from the front since my placement is high. I mounted the main left and right tweeters at the top of the A pillars and then I decided to put the supplimental tweeters inside the sunglass storage, so i can hide them away when i want to. The sunglass compartment tweeters are the right channel driver and left channel passenger.
In the trunk I have a 12" Eclipse sub, which is sufficient for the bottom end I want to hear--I don't want the "ghetto trunk" sound and I don't listen to rap.
Driving the main speakers is an Alpine 4-channel amp, about 50 watts RMS per channel. The sub is driven by an Eclipse 100 watt RMS mono amp.
The head unit is a JVC EXAD unit that has a touch screen. It also has an SD memory card slot hidden behind the face that plays MP3 and WMP files. And then in the top armrest compartment I put in a Pioneer Inno XM unit that I have run directly into the JVC's line-in connection.