12/12/2014:
Have two vehicles on All Access, one also has travel and traffic services. Called in to renew, offered to pre-pay for full year if I got a discount. First CS agent couldn't do anything (other than 12 monts 1 free), so I requested to just cancel both accounts and not use XM. CS agent transferred me to a second agent to process the cancellation, that agent helped me downgrade one vehicle to 'select' and pay half-price on 'select', then kept the second vehicle at All Access with traffic and travel for half-price. So I pre-paid one year one both, saved some significant $, still get navigation, traffic on the primary auto, and I still get internet radio.
Not a bad deal, but very annoying they make me do this dance every year. I've had XM radios (portable, then cars) since 2005, and I have to do this ceremonial 'threaten to cancel' routine every year.