I guy I know who works as a Grip in Hollywood sent me details on a Panamera Camera car.
GearPatrol panamera-turbo-camera-car
Lots of work and $$ in that platform. I would have thought it would have been better to start with a ground up purpose built design but then maybe costs would have been higher? I'll bet that whoever negotiated the Pcar ended up getting a personal Panamera/GT2-3 car(s) out of the deal.