Jon Hilkevitch, a transportation reporter for the Chicago Tribune, writes about a lesser-known feature of in-car automation systems like OnStar. Many of these systems, including those in BMW automobiles, automatically notify their operations center if your car is involved in an accident.
This is so the center can dispatch help to the scene of your accident. I recall an OnStar radio advertisement that dramatized this futuristic scenario from a while back. "This is OnStar. We have detected that your airbags have deployed and are sending an ambulance." Thanks to the GPS-aware system, they know exactly where your car is located.
But in addition to calling for help, the center can (and apparently does) notify your loved ones. The story talks about a man getting a call, on all of his phones simultaneously, when his wife's BMW was involved in a rear-end accident. He was able to rush to the scene and help her; arriving just shortly after the paramedics. A few years ago I was in a bad car accident just a few blocks from home, but I was able to call my wife myself. Having her arrive on-scene was a great relief to me, and I can certainly see where this feature, despite the stress it might introduce, could be very helpful.