I am having exact same problem. I purchased my 2007 chevy silverado used. The dealership is giving me the runaround and can't seem to find the XM Radio ID and didn't provide me with the XM Radio manual and cant even tell me info on brand of factory installed XM Radio with AM/FM/XM with single CD player. They told me it is XM Ready and said they don't ask for all this info from previous owner when taking in a used vehicle. Can I go to any chevy dealership? How do I remove the radio to get the info? What are all my options? Thanks