I called Sirius about it. They said I need a second subscription to use it in the Tesla (the main is in our Subaru Ascent). Naively, I thought that it was good for both cars. We have used the Ascent a lot less in the pandemic and we use Sirius veru little anyway. I'm certainly not going to have two subscriptions, so I am going to leave it as is for now. Maybe sometime I'll switch it to the Tesla. Sorry if I confused anyone (I mean, besides me!).