Metra's GMOS-01 interface lets you replace the factory radio in select OnStar-equipped 2000-up GM vehicles using the existing wiring and connectors. Even if you don't subscribe to OnStar, you'll need this interface to connect an aftermarket stereo.
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.