My wife and I were stopped in Salisbury, MD by a MD State Trooper about 7 PM on a Friday night because I had a clear cover on the license plate. I've had them on every license plate on every car I've ever owned. Now it seems that some of them obscure camera pictures (I had no idea, nor did I know it is illegal to use any clear cover in MD because of that) so now my license plates are no longer as clean or as easy to clean and wax. There should be a way to test them or something.....perhaps a cell phone pix would spill the beans?