Robot car function I just thought of: will a little kid, lost in suburbia without adults around, be able to walk up to a public robot-car and say, “I’m lost, help me!” and that will trigger facial recognition software, access the parent’s emergency contacts and emergency account protocols, and the car will go into comfort mode, invite the kid in to give them somewhere safe to sit while the car facilitates Skype calls to the parents, calls the local police , etc. The parents comfort the kid while they approach the car in their own robot-cab.
Eclipse Now 
Just a thought, from personal experience.
No stranger should ever take a lost child to their home. The general case is to arrange for the police or other relevant authority to be contacted and to stay with and comfort and reassure the child until the police arrive.
That applies equally to kidnap-by-robot-car.
I suggest that your scenario be altered to something more akin to “child or passerby pushes the alarm button on the driverless EV. EV sends photo and location to the police. Passerby comforts child. Etc. The child should not be moved by unauthorised people or vehicles; that is baby-snatching.
Come to think of it… why would the car do anything at all? The passerby can handle this via mobile phone.
Now,if the child or an incapacitated adult was INSIDE the EV, the situation would be different.
Good point Singleton, and I’ve edited the post to make it an citizen helper free scenario.