I ran afoul of a parking attendant in LA when I did a car restoration. Should have learned my lesson but ended up with 3 tickets while parked, even with plate displayed in the windshield. Never pulled over for it, but some people are sticklers.From my experience they don’t enforce it in CA or MN. I drove 40,000+ miles a year in CA for over a decade and never got pulled over for not having a front plate on either of our vehicles. I got a few speeding tickets and they never tacked on a violation for my missing plate. I’ve lived back in Minnesota since 2018 and I’ve also never been ticketed for a front plate.