Forgot to mention.... usually a week or three 8-) after you take delivery of a new vehicle with XM that a dealer has activated the vehicle owner will get in the mail a card that has the XM radio ID# on it, a note Welcoming you to XM Radio and a list of different subscriptions you can purchase after your 3 month trial ends. With this info in hand -- the radio ID# specifically you can then go to XM's website and set up an account. Once you establish an account you can purchase your subscription and much more there. Here is XM's internet address--
XM Satellite Radio - America's #1 Satellite Radio Service
By the way Sirius works the same way.