I am in the process of getting everything together to install in my car.
So far I have a boston 12" inch sub, Eclipse 5 channel amp, Alpine type X compeonts, 36sq of dynamat extreme, and an Eclipse CD7000 single din GPS Nav unit. I want factory look but have decided the easiest route is to rewire the car for my application. If you want to amp the speakers and the sub, you will need to cut the wires and bypass the factory amp. If you just want to amp the sub, then use a rca converter and tap the rear speaker wires. If you need a wiring diagram, search the audio forum. I needed one and there is a link to it somewhere in that area.
<span style='color:gray'><span style='font-family:Courier'>1995 e36 3 Series RIP
1999 e46 3 Series BURN IN HELL
2000 MR-S Roadster= Current</span></span>