This is such an amazing idea. I've already thought of two things it might be useful for: a) No headphone cords when running. b) No headphone cords if you fall asleep (just in case they get wrapped around your neck)
The heads-up display allows you to look at data on your windscreen and you can return calls or send text messages through voice commands. A great way of avoiding fumbling for your phone so you can keep your eyes on the road.