is there an rpo code to indicate if the vehicle has wiring for the xm module. i have a 12 LT as well and i have the same problem in which i dont have the xm reciever unit installed. i have done some looking around and cant find much. what i did see was that some people who have purchased that insanely expensive upgrade kit did not have all the wires behind the dash and had to pay a lot to have new wires run for say the antenna. i was also wondering if the touch screen uses the same xm reciever as the stereo with the large knob in the middle? and will the xm reciever unit effect having the usb port on my dash??