WTf, I swear I was developing a way to do something almost exactly like this. Except mine would be mainly for cars imported and built in the US and main use in the US.
It would suck for people who feel the need to speed but every new car built and imported into the Us would have an intergrated GPS which sends your speed signal to whoever, *DOT for that specific state*. When they verify it was speeding, guess what the registered car owner gets in the mail?
It would drastically reduce insurance rates, lower highway patrol, most likely lower some other random state taxes because you know damn well people will still speed and be getting tickets in the mail, it would also keep the roads safer but your speed isn't limited. If you decided to modify your car, that's fine but it would be under a completely different class and not be able to be "street legal".
Every registered car would need to go through an inspection and installation of such device to make sure the device was active even in older vehicles. The states would have to come up with a new plate for the cars that do have it and eventually all registered cars would have this state specific plate.
But, even if I did finish it, I probably wouldn't release it because I like to speed.