My sister won a free lifetime subscription many years ago, then sold the car it was on. She told me I could have it if I could get it transferred. So about a year ago, I called with her login info and got it transferred to my 2008 Corvette. They did not charge me a thing to move it. Got it merged with my existing account and all was good.
I sold the 2008 Corvette two weeks ago and bought a new C7 Corvette. I literally just called them 30 minutes ago, moved the lifetime sub to the new Corvette and they did want to charge me $75 this time, but I acted very upset and surprised that they want to charge me just to move the radio over. Supervisor waived the fee and I now have lifetime on my new car.
It can be moved, worst case you pay $75, but act shocked and in disbelief that you have to pay to do something so simple on their part and it will usually get waived.