Boy hit by hybrid car; mom says he didn't hear it coming

I want a Hybrid car...but something to think about

I have always enjoyed the look and concept of what a hybrid car can do. I've had the chance to hear them too and they are very quiet, but now it looks like this could be a problem. It would be great if we could create something that could create an alarm of some kind when a person or object steps in front of the car.