Yellow, don't get me started on that!! Ha. Originally our state Legislature gave us a "rolling" smog exemption, wherein the year of smog exemption would increase with each year that passes. But after a couple of years under the rolling exemption, the feds happened to give the State of California the evil eye about not meeting their air pollution goals, so the state somehow tossed out the rolling exemption. I do not understand how they overrode the vote of the Legislature this way.
Yes, the very first thing the state did to convince the feds they were going to roll over, play dead and let the federal government have their way with them was to offer up the rolling smog exemption as a sacrifice to the nanny state, despite the Legislature's intention to give the citizens a rolling smog exemption, and nobody ever took it to court. So we no longer have the rolling smog exemption and the exemption date is forever written in stone as 1975 and older. Unless somebody takes it to court, perhaps.