California Vehicle Code section 26708: No person shall drive any motor vehicle with any object or material placed, displayed, installed, affixed, or applied upon the windshield or side or rear windows.
27602. (a) A person may not drive a motor vehicle if a television receiver, a video monitor, or a television or video screen, or any other, similar means of visually displaying a television broadcast or video signal that produces entertainment or business applications, is operating and is located in the motor vehicle at any point forward of the back of the driver's seat, or is operating and visible to the driver while driving the motor vehicle. (b) Subdivision (a) does not apply to the following equipment when installed in a vehicle: (1) A vehicle information display. (2) A global positioning display. (3) A mapping display. (4) A visual display used to enhance or supplement the driver's view forward, behind, or to the sides of a motor vehicle for the purpose of maneuvering the vehicle.