Been around since 2010 in BMWs...
http://www.euroncap.com/en/ratings-rewards/euro-ncap-advanced-rewards/2010-bmw-assist-advanced-ecall/
Got this in mine, it contacts BMW first (112 direct if unable to reach them) with sensor data and establishes a voice call so its fleshy occupants can then tell the lovely person that you do/don't need the emergency services as required. Plus button to press up on the ceiling should you witness an accident and need assistance or be in something minor enough that it doesn't make the automatic call and you really do need someone.
As it screams at BMW, it means that the onus is on the car manufacturer to get good quality sensor data / provide a system that doesn't make a call to the boys in blue every time a fly hits the windscreen.
If you're the one unconscious you'd probably like to know that the emergency services are already being alerted before other witnesses/injured souls have probably even gotten their phones out of their pockets/figured out if they're still in one piece/which way is up. Hopefully I never have to use it of course but its something I hadn't even thought about since the dealer gave a quick blurb overview of it... until this article anyway :)
Biting the hand that feeds IT
