Cops are too busy chasing 150 mph cars that drive 80mph on US roads, so they don't spend time on chasing red light runners and even less broke lights or obscure licence plate.
CA require front licence plates, but good luck finding Porsche or Vette with one.
On other hand, I was in traffic court few years back and about 50% of cases there was when the cop pulled a car for technical malfunction and found marijuana in it.
I take it the driver rose suspicious and broken light was just excuse to pull him over.
My camper has LP holder under the rear bumper, what is 4" square tubing holding stinker hose in it.
You won't see the plate unless you go at least 25' behind the camper to get the angle of view under the bumper.
I spoke to a cop about it and he did not see any problem.