Calsenator

mine definitely works especially if your not looking at the road, it becomes more sensitive to objects or speed changes. No good way to test it. I remember getting it to go off at like 10 mph in a parking lot as I pulled up behind someone waiting at the traffic light while I was looking at my cell phone for directions. Mine is 2013 and I believe that year it doesn't auto brake for you. It will only help you brake harder if you press the brakes when it alerts you. I believe later models are updated to actually brake without your help. But I'm not sure if it will actually prevent a crash.