yeah that shit kinda tweaks with my brain a little bit...
thats all we would need, cops with the ability to see when our cars are throwing codes. then, pull us over and give us a ticket... probably several cuz once you know there is a "problem" they are gonna check everything...
not to mention the whole monitoring a relatively private thing...

if they want better emissions, get the really old clunker cars off the roads... you know the onces that smoke like hell as they fall apart down the road...
then from there, make it an option to get tested. you can go get tested, or you can pay "X" dollars a year.
once you get tested, you'll get put into different tax catagories. some cars are gonna be alot "nicer" to the envirnment, give them a huge tax break. those that are in the middle, an average tax break. and those that are on the bottom (but still passed) like 5 bucks...
and then the ones that fail, can either fix their crap or pay the annual fee....
they would just have to make the annual fee high enough that your average person wouldn't want to pay it... and they would have to make the tax beraks big enough to make it worth it to everyone...