I see at least two ways to implement that, but I certainly don't see how practical they are, if implemented at scale:
1) Every component has unmodifiable update logic that supports just that: factory reset for itself, and propagating it to the subcomponents.
This is still where we can say "the owner does not own the car", but in this case it could be treated as a part of hardware (that could not be modified either), rather than "user-space" firmware.
2) Allow easy reinstallation of the critical electronics components, which can be bought from the manufacturer. I don't quite like this "hard" way, but it's a possibility.
I see at least two ways to implement that, but I certainly don't see how practical they are, if implemented at scale:
1) Every component has unmodifiable update logic that supports just that: factory reset for itself, and propagating it to the subcomponents.
This is still where we can say "the owner does not own the car", but in this case it could be treated as a part of hardware (that could not be modified either), rather than "user-space" firmware.
2) Allow easy reinstallation of the critical electronics components, which can be bought from the manufacturer. I don't quite like this "hard" way, but it's a possibility.