Alright fellas, im trying to install my amp and subwoofer into my 98 a4 w/ concert system.(its says bose and concert in the dash, booklet stays concert) i have a stock 6 disk changer in the trunk and no factory subwoofer. also, im trying to keep the stock headunit, but i have a sony if its not possible otherwize

Ive read around and i found a guy who had installed the same thing into the same car, yet the wires he defines in his guide dont correspond with the wires in my car.
http://www.audiworld.com/tech/elec29.shtml

i was wondering if anyone knew where to find the stereo wiring diagram for my car, or if you guys had some tips that would be helpfull also.

thanks

 

stereo wiring diagram is on top of the chassis of the stock HU.