The C2R-GM29 allows aftermarket radio installation without retention of the factory radio. The interface replicates all factory warning chimes, audible turn signal indicators and provides a data bus generated 12 volt accessory output that acts just as GM's R.A.P. (Retained Accessory Power) system did prior to radio removal. R.A.P. keeps the radio powered after the key is off, until the driver door is opened or a 10 minute timer ends, whichever comes first. The C2R-GM29 also provides a SWC (Steering Wheel Control) output wire at the interface. By using this interface, the Parking Assist System will receive a “healthy” system status and the Rear Seat Audio controls will also be available for use (if equipped).