If two people run out in front of the car, and my option is to swerve to take out one innocent person on the side-walk, should I stay on the road, harming the people who broke the road rules? I would be breaking the road rules if I swerved and also I'd be harming someone who did no wrong.
I'm not sure it's true they must be programmed to kill. In general they will be programmed to avoid killing anyone. I imagine in situations that they do kill people it will be because the systems failed rather than by calculation.
... or we could just program an external airbag in the radiator instead and be more creative. A "capot airbag", why not? People in an automatic car do not really need to see out to drive.