One person stands in front of the car to stop it. The next person smashes a window and jumps in. What comes next is a guess, but they would probably do somethin

One person stands in front of the car to stop it. The next person smashes a window and jumps in. What comes next is a guess, but they would probably do something to override the controls. I imagine that there must be an override button on the car somewhere, otherwise you have literally no control over the car in the event of an emergency. I don't know that they can prevent it through fail-safes. I think they can discourage it, at best, but as with any system, people will find a way to force the system to suit their needs.