It's pretty lame to claim there is any first amendment right to put any lights you want in any configuration you want on a car that is driven on public streets.
https://isalegal.info/christmas-lights-on-car-legal-california/
Yes, it is legal to put Christmas lights on your car in California. There are no specific laws that prohibit this, so as long as you are not obstructing your view or driving in a dangerous manner, you can decorate your car however you like.
“It’s pretty lame to claim there is any first amendment right to put any lights you want in any configuration you want on a car that is driven on public streets.”
Ironic that some states would prohibit Christmas lights on my car but in all fifty states I can drive around with the word “MOTHER****ER” painted on it and that’s a protected right.