Followed the Sirius link in the article to their privacy policy: https://www.siriusxmcvs.com/privacy-policy/

> Vehicle Data... After your Vehicle’s ignition is turned off, the Vehicle transmits the location of the Vehicle and the time it was turned off.

If every car with Sirius installed transmits the time and location when it was switched off to marketers, that would close the loop on all those "I just moved to this place and I'm getting local robocalls to my cell number".