You cannot add features to the car because Porsche does not use standard wiring harnesses, leaving empty connectors dangling. If you dont have the option, the wiring will not be there. You can add it manually since all the wires are individual, just wrapped in fussy tape but it is a time consuming job. The Bose and Burmeister subs connect to the amplifier under the passenger seat carpet, so without that, I cant see how you can add it.