Edit: Just asked because of curiosity. I’m not actually looking for such vehicles.
Edit 2: So for context, my parents new Toyota has this feature that allows the GPS location of the car to be sent to toyota, then you can see the location via an app on android/ios (it’s supposed to be an anti-theft feature). The data is sent via an antenna that connects to cell towers, which then connects to the internet, and to the toyota servers. “Diagnostic” and “maintenance” information is also sent via those same antennas.
The dealer said it could be turned off, but who knows if they are really off. There’s not a hard switch on the car.
While this is probably the only real solution for complete peace of mind, you may be able to find and disconnect the fuse to the telemetry system as an easier (and cheaper) fix - check out the fuse box diagram in your owner’s manual!