It was only avalable in 86-88 with the option code UQ6. There is no difference between those years either. It pertty much consisits of the following parts: Amp, Overhead slide control, and subwoofer in housing. The housing is located under the passenger area right next to the heater core. The amp is under the carpet in a plastic holder next to the passenger's feet. And the overhead slide control is of course overhead.

Make sure you get the wireing harness cause it will save you a lot of headaches. I got my whole setup from a junkyard and took maybe a couple hours to put together with a new Rodney replacement sub. I have a very lengthly installation sheet i think if you wanna route the wires and stuff exactly like from the factory. Let me know if you want it il have to find it and send it to ya.
Jason