Mine died this afternoon; all of the presets vanished, and I only got the "XM Preview" stations.
I called the number on the screen (800-643-2112) and sat on hold for about 10 minutes. The rep asked me for my radio number (had to park and de-activate Bluetooth; the radio number displays on "Channel 0"), and set me up with a new account. They offered: a) 5 months for $24.99 ("A 60% discount!!"), or b) one year for $95.
I took the year, which comes out to $106.25 or so with "U.S. music fee and applicable taxes".
All my presets returned intact in a few minutes, as promised.
90 days back would be March 10, which was just after my VIN/Carwings, and about 2 weeks before I took delivery.