Problem: Installing an aftermarket receiver in some 2000-up General Motors vehicles with OnStar means losing OnStar functions, as well as other audible safety warnings.
Solution: Metra's GMOS-01 GM data bus interface lets you replace the factory receiver in these vehicles while keeping OnStar, along with the door chime and audible safety warnings. Hook the GMOS-01 to your aftermarket radio, mount the module, and plug it into the existing factory plug. Get the great sound you want, and keep all important safety features intact. And you can adjust volume settings for OnStar as well as the safety chimes. Also, once you turn off the ignition in these GM vehicles, the radio continues to play until you open the door. This interface maintains that function with your new aftermarket radio. This interface is compatible with select 2001-and up GM vehicles.
Note: The GMOS-01 will not work with factory-installed Bose car audio systems
So what the local shop said is true, you will need this rig.
Problem: Installing an aftermarket receiver in many late model (2000-up) General Motors vehicles means losing ONSTAR system functions, the Bose amplified speaker system, audible safety warnings, and the chime that warns the door is open.
Solution: Metra's GMOS-04 GM Class II data bus interface lets you replace the factory receiver in these vehicles without losing these functions. Connect your in-dash receiver to the GMOS-04 interface's RCA input jacks. You'll get the great sound you want, and keep these important features intact. The Bose amplified speakers and the ONSTAR system will operate with your new radio, as well as the door chime and audible safety warnings.Also, once you turn off the ignition in these GM vehicles, the factory radio continues to play until you open the door. This interface maintains that function with your new aftermarket radio. This interface is compatible with select 2000-and up GMC, Chevrolet, Oldsmobile, Cadillac, Pontiac, Isuzu, and Hummer vehicles.
The Wheel controll, that may be tricky. The PAC's SWI-X interface is designed to adapt to the remote. So as long as there is a remote with this head unit the PAC's SWI-X interface should work. This box basicy acts like a remote and turns you wheel controlls into a remote.