[justin66]

Even in some scenario where crappy-car owners are some kind of especially pernicious safety menace (a claim for which I would demand actual evidence, since I don't believe it for a minute), I can't imagine what it would be like to live in a place in the United States where there are so many cars on the road that are legally undrivable for safety reasons that their removal would make any kind of significant difference. I read "astonishingly high effect" above and wonder if you even drive in the United States.