I believe that OnStar is an extra cost option.
A friend of my brother's was on vacation when OnStar called him and announced that there was a recall on his new Chev, and that he needed to have it fixed immediately. He told them he was on vacation, but they said if he didn't get it to a dealer immediately, they would just disable the vehicle until it was fixed. He lost 3 days of his vacation waiting for the part to come in at the local dealer.
Anybody still want OnStar?