Looks like it has some good uses, but also some dumb ones. Hearing a beep everytime I exceed the speed limit or accelerate aggressively would get annoying. And you may not always want the authorities to be notified if you have a minor fender bender.
"Stepping hard on the gas pedal decreases fuel efficiency and wastes money."
Actually it decreases fuel efficiency and increases driving pleasure, which is always a worthy investment.