Does a stock 2003 Audi A4 stereo have subwoofer ports?

I have a 2003 Audi A4, no navigation and not bose. It has a positive wire and a ground wire coming through the car already from the previous owner. I do not see a rca wire to connect from the stereo to the amp, i was wondering do i need a new stereo or does the stock one have the rca ports?Does a stock 2003 Audi A4 stereo have subwoofer ports?Where is this "positive wire and a ground wire coming through the car already?" No, neither stock headunit has RCA ports.