In mid-July I extended my XM subscription for 6mo. for $38. In mid-September I bought a new car with a 3 mo. trial XM subscription. Since the trial is about up, I called to tell them when the trial expires that I wanted to use up the credit from old subscription before deciding whether to go forward. That was OK but they would only credit me for two more months not the 4 more months that I had remaining. I said in that case I'll take the two months and then they could cancel my subscription because I was not going to pay $16/mo for XM. They also said that I could not call in advance and I had to call the exact day that it expires or they would bill me for another month. They never mentioned anything about extending my subscription for another year for $77.
They are not very customer friendly anymore.