Bring it on in if you want to be an idiot, they will write you up or impound.
It would be legal here... well maybe not legal (can't get busted if the laws are not enforced), but as long as I have a windshield, and two mirrors, I should be good to go. I don't understand why California has to be so controlling of what people do. I see nothing wrong with driving a truck with no hood, fenders, doors, bed, or muffler. But I guess that is why I will never live in California, just too many rules.