Automotive magazines have done tests with different types of cars, and different types of Radar guns, and not all cars are created equal when it comes to their "Radar signature". Some vehicles need to be a lot closer to the Radar guns location for the radar to get a good reading.
A cars front plate helps level the playing field, and gives any car a better radar signature.
Everytime somebody in Ohio gets the bright idea that they could save a lot of money by only making one plate per car, the Ohio Highway Patrol instantly lobbies to keep the 2 plate system for adequate Law Inforcement.
Makes me wonder why Law Enforcement agencies in so many other states can do their jobs quite effeciently, with just one plate, but not the Gray Bears in Ohio.