I dont know about the cable, that is new to me, but it would be cool if it was the case. As far as head units, what I did for my 2002.5 P5 was research on Crutchfield.com what I needed and then purchased on Amazon. Got a great Bluetooth,Satellite, HD Radio, iPOD ready Headunit (ALPINE) from Amazon for a great price with, and this IMPORTANT, the connector between the head unit and the factory wiring...no cutting required, plug and play...You will also need a headunit surround (aka Trim Panel). Crutchfield.com will walk you through what you need...even tools too! Good Luck!