The hiding license plate was a favorite trick in the Fast and Furious movies, in the theme for the second movie Ludacris mentions "hideaway license plates". Tolls must be different on the east coast than out west, because here we have actual toll collectors. But then again the only toll bridges are in the San Francisco and Seattle areas, and there's a handful of toll expressways in Los Angeles. Looking at a map, there's tons of toll freeways back east, with toll booths every 5 miles or so, so staffing them all would be too expensive. West of Chicago there's only a couple of real toll freeways-turnpikes in Kansas and Oklahoma, I think-until you get to the coast. I bet that the hinged plate is to avoid cameras that snap a pic of your plate if you don't pay, like red light cameras in California. Out here people just refuse to put the front plate on, and the cops are stretched so thin that they can't make them.