My Z's have always been testbeds for whatever product I was working on at the time. I've had some awesome stereo systems in them and I've had some crap. Now that I am one of the guys in charge of the company making what goes in my car I don't have to worry as much about the crap.
Current headunit is a Pioneer AVH-P7600DVD. It's a single DIN flip out touchscreen dvd unit. Actually pretty nice except it doesn't have the navigation built in. You have to buy that seperately and they are stupid expensive even on 5 yr old units.
The car currently has two amplifiers. The front is a modified Linear Power 2202. In stock form it will produce 110+ watts into a 4 ohm load on each channel. Since Ray modified it the sound quality has gone up (surprising in istelf) and 4 ohm power has gone up. I won't speculate since I haven't tested it to know for sure.
Front speakers are a Blues BL65CP component set. That's a 6.5" woofer in the door in a fiberglass build out. In the A pillar is a BLt1 soft dome 27mm tweeter mounted just above the dash cluster horizon. This makes the soundstage of the car about 9 feet wide. Oddly enough your ear is not drawn to the pillar like I initially thought it might.
After initial placement of the mounting cup on the A pillar.
The crossovers are prototype units I built by hand before our production units were finished. They are the exact same thing but in a Radio Shack project box instead of the fancy blow mold cases we have now.
The sub amp is a modified Linear Power 952. Again, in stock form this amp produces about 100 watts into 4 ohms. I'd say in current form it will do that into an 8 ohm load with incredible control and clarity.
We never intended these amps to be low impedance / high current amps. They produce a lot of power for their size but are incredibly efficient doing so.