At first I wondered what the hell the point of this tech is, but then I realized it'd be government-mandated "black box" on each car. Why would a driver want something gimmicky like this (ads on cars? How many square yard of ad space do cars have already?), but if it's mandatory, then, that's the point of the tech.

Use mesh networking and cars can tattle-tale on others, "The Hyundai with the expired tax went that way, auto-cop!", and it'd be easy enough to spot because the display will be blinking "Expired tax" instead of showing the plate.