Bought a car with a 6 month free Sirius subscription. Use the radio all the time. When the 6 months was over, Sirius stopped working.
Bought an RV with a 12 month free Sirius subscription. Rarely ever turn on the radio. We visit. That was over 7 years ago, and about once a year I turn on the radio to check the Sirius subscription. Still going strong. I figure that with the radio turned off, when Sirius sent the disable signal, the receiver never got it.
In 7 years, we have not logged 30 minutes of Sirius listening.