It was there installed in our office cabs....The moment,...they track the vehicle, they track the speed too....The moment speed get past 50-60 driver used tobget a call.....The GPS did helped to track few of stolen cabs ..... but at times when the office running short of the vehicles they themselves asked the driver to increase the speed to cover up.....as said every invention has certain pros and cons....if we strictly adhere to certain rules and then the world would have been a better place to live in.