I think the problem here is more that the car has a network connection. I’m not sure how you could feasibly have an EV that isn’t fly-by-wire (meaning controlled by a computer or microcontroller).
Even something like a BMS is, in and of itself a computer.
The only wireless connectivity a car should have is Bluetooth to connect your phone to the head unit that is disconnected from the rest of the car.
It’s be nice to see some kind of modern EV run fully open source software.