A lot of progressive leaning regions are actively trying to slowly legislate cars out of existence, see the camera system in the UK that's being sttacked by the so called "blade runners".
Fact is cars are real freedom, and the next time the government declares a pandemic and determines that public transit is too dangerous, a car is your only movement option for going outside of bike range.
the gubbermint is coming to steal our cars so we have to live in their bicycle dystopia 
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Does that not get them pulled over by the cops? I guess the cops would use some other method to determine whether someone should be pulled over over there.
What I typically see is they attach fake temporary plates to avoid scrutiny. They’re easy to fake, especially in the US where they can fake a state other than the one they live in and thus the cops are less likely to recognize them as fake.
I see. Over here the usual thing to do is to steal someone else's plates and put them on your car.