I can't for the life of me figure out how those shaded license plate covers -- which are marketed as a way to protect your poor fragile license plate from the harsh elements, but are clearly meant to obscure your license plate from police and speeding/red light cameras -- are even remotely legal.  I'm guessing they're either (a) not as effective as people think, i.e. a cop will get your license plate number when and if he/she actually pulls you over, or (b) completely useless because camera lenses are polarized or something like that.