Some of the Californian law codes:

OFF THE WIRE
California Vehicle Code 23110 addresses the illegality of throwing any object or substance at a vehicle in operation. According to the code, any person who throws anything at a vehicle or occupant of a vehicle while the vehicle is being operated on a highway is guilty of a misdemeanor.
Code 23110 also notes that if a person intentionally attempts to cause bodily injury to a driver or occupant of a vehicle by throwing a rock, brick, bottle, or any other object at a moving car, it is considered a felony. Any intention to cause bodily harm to a driver or other vehicle may be punished by imprisonment.
https://www.youtube.com/watch?v=5Jox3r36z_U