98 Eldorado Bose Wiring

I'm about to start a major overhaul on my Bose Stereo system in my 98 Eldorado. I plan on keeping the factory head unit to maintain the stock look but I am using a Rockford Fosgate sound processor to clean up the signal. They claim the best place to tap into the wiring is after the amp because it has the hottest signal. Now I have two questions. Where is the factory amp/amps, and what color are the speaker wires? If anyone has or knows the location of a wiring diagram for the bose system, it would be greatly appreciated. Thanks!