[GingisK]

Then you have some other sort of tracker in your car. Does your car have a Google-linked GPS device that you use for navigation? Has someone put a tracker on your car? GPS satellites do not receive anything from GPS devices. That is a one-way communication.

[AnglePark]

No, I don’t have navigation in my car, and that’s why I use my phone (Google Maps) via Android Auto.

In this case I went to PetSmart without my phone, and when I got back there was a Google notification (question) asking about my visit to PetSmart. My first response, of course, was “how did they know?!” That (usually) only happens when I have my phone with me, or when I’m using Google maps when traveling.

I suppose it is possible Google is monitoring my movements/purchases via another method — i.e. credit card — but no matter how it happened it shows Google’s reach throughout society, smart device or not.

[AnglePark]

GPS satellites do not receive anything from GPS devices.

The car is XM compatible (I've never subscribed), which is why I pointed at satellite connectivity initially. There has to be some two-way communication for them to verify your account/vehicle.