I have a 2018 Chevy. I get emails from the dealership that tells me when a light goes off on my dashboard. OnStar will give me monthly reports about my driving tendencies (average speed, aggressive acceleration, etc.).
So now that I know big brother has access to my car, am I able to disconnect it from the grid?
Theoretically a killswitch could be built into the keyfob/TPMS receiver.
3G sunset was July. 2G sunset was said to be December, but 2G is still going. A 2018 probably has a 4G modem so that will probably never go away. Communication systems these days are nearly perfect, very close the Shannon limit, the theoretical amount of information a communications channel can send through specified conditions. The new advances are just increasing the signal width, number on antennas on devices, and new frequency bands. Hello, millimeter wave 5G.