Here goes, the system is eleven speakers driven by a seven channel "Bose" amp in the trunk over the drivers side rear wheel. Very prone to fail with popping and distortion. The "control" in the front is just that in addition of being a cassete player. The out put of that is a large din that goes to the "tuner" at the base of the rear wheerl. If you have the CD the lead is routed thru it and back to the tuner.The two channel output is routed to the "Bose". There are two speakers in enclosures in each front door, there is one speaker in each rear door, four speakers on the rear deck, 2 (2) ohm wired in series for bass. There is a tweeter behind the rear view mirror, the outboard speakers on the dash are for the CTEL option, and could be installed, they are tied together and the wire runs into the antenna area in the trunk. The front to rear is handled by the fader switch in the console. There is no antenna lead in the front, it goes to the tuner in the trunk.
To get out the back seat requires some extraordinary skills since panels have to be removed, heated seats and electric headrests add to the fun. The gas tank is positioned in back of the rear seat, and the wires are in looms along the door sills. Has it been done I think so, but not very often! That should give you something to ponder, some of those looms are pretty dry when it comes to insulation flexing and slicing and splicing could get you other issues.