Seems like you’re grasping at straws to find weird edge cases that don’t at all preclude a mostly self driven future. I don’t think these cars will be made without steering wheels, or a mechanism to control the vehicle directly.

But I bet they get a report of how often you manually drive and if you cross a specified threshold your rate increases.

Edit: Also why would you need to park on grass! Hop out of the car and it will park itself wherever in a nearby lot, or just drives around until you need it.