alt Hacker NewsEven within California there are smog-exempt counties. This makes perfect sense, things like excess NOx simply don't matter if the population density is low enough which incidentally is also true of a lot of the rest of the country. CA is the strictest with smog-related, going as far as barring federal (non-CA) vehicles from being registered unless they're 7500+ miles on the odometer. Tint should be limited to 70% VLT nationally really, but that's another topic. Other than that some north-eastern states have safety inspections which makes total sense given the rust. By developed country standards we have it very easy.
I ran into a fun one when moving out of the country. Chrysler Town and Country I had bought in Washington state, we were flying out from CA. My thought was to unload the vehicle in the last week before flying.
Except no one would buy it, not even Carmax or any of the other "cash for cars" places! Turns out, the car was originally manufactured for Canada, and California doesn't recognize the Canadian smog regulations, even if the car was functionally identical down to the catalytic converter. No one would take the damn thing because they couldn't re-title it. I finally found one guy who would who seemed like he was taking a decent sized risk, but since I gave him a good price he decided he'd just give it his best shot. For all I know he may have had to (illegally) drive it to Nevada just to sell it.