I'm trying to install a Bluestar in my 2005 Tahoe, but I can't seem to find the Onstar unit. I''ve ripped out the stereo, looked under the glove box, but don't see anything. I would remove the chassis that the stereo mounts to to look behind it, but it appears to be held in place by rivets. I've heard that in some cars it is next to the passenger airbag, but I am hesitant to remove the cover for that as I don't want that to go bad. Any advice will be appreciated.