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.
Your best bet for a “hardware switch” is reading the service manual to find which fuse controls the comms module, and pull it. Depending on the vehicle it may have other side effects.
Maybe we will get to the point where people are selling modchips for cars, like the OG PlayStation.