Washoe County, Nevada has not had smog tests for decades, maybe 18 wheelers I don't know. I live in Douglas County and no requirement for smog tests.
I recently needed to re-register my Jetta and the computer I was using was a no-go.
Someone either in Douglas County, or in one of trips to Reno, a complaint was filed I was rolling coal, and therefore my car needed to be inspected before I could register my Jetta. Holy crap, and bunch of other choice words ran through
through my mind. My injection pump IQ left a bit of smoke, but very little. A very nice lady at DMV asked me if my car weighed less than "X" ( I don't remember the number ) I replied, "Yes" and she took the hold off of my registration.
There was actually more conversation, but not important. Maybe, just maybe, the vehicles that are rolling coal and making the rest of us look bad, will have to de-tune, or make smog compliant vehicles.
TBH, I was a bit angry when I found why there was a hold on my registration, and then I had an epiphany... the hacked up/jacked up trucks. I have a healthy tune in my Jetta, but I have enough turbo to not roll coal.