Now you're just changing your plan. You said a card implanted on the plate. The remote data transfer plan you now cite is not a new idea. People have posed idea like automated speed monitoring equipment that notify the police when to send speeding tickets, but who wants big brother in their lives like that? Just so some people can drive a few miles an hour faster than others? And that sending device, if we are being realistic, would have to be attached to your license in you pocket, not the plate, as otherwise you would no longer be able to loan your car out to friends or family without screwing up your entire automated plan. Attaching this speed reading device to the cop's radar gun is pointless as well, if you want an automated system we already have satellites capable of telling you (or anyone who could 'read' your info) what speed you are traveling. And your new plan still doesnt address the problems caused to traffic flow and the driving hazards that would cause.
On a side note, many people with enough DUI's these days get a breathalyzer placed in their car. It *does* monitor speed, which is saved on the local HDD that cops monitor monthly, and (at least in some states) can lead to speeding tickets after the fact.