www.radiosandmore.com/prod_detail.asp?pn=RPR-D-001-bmw, this xm is a plug in for factory head units .....mabe the 6 disk that comes with the av, check it out. look under sat radio
That is a plug and play for the bmw. The same technology but a different protocol and interface would be necessary for the GM application, which I am sure is not far down the road.