Comment by reaperducer

Is it possible to disconnect the power from the radios used for "over the air" nonsense? Then at least they would be stable.

I've read online that for some cars, you have to dig deep inside to disconnect the cellular antenna.

I'm a little more lucky. On my car, you can pop out the SIM card from a slot in the ceiling, behind the rear-view mirror.

This assumes you haven't given your car access to your home WiFi. (Some people do this so they don't have to pay for a data plan for their car, and it kinda sorta "syncs" when you get home.)