321.37Display of plates.Registration plates issued for a motor vehicle other than a motorcycle, motorized bicycle or a truck tractor shall be attached to the motor vehicle, one in the front and the other in the rear. The registration plate issued for a motorcycle or other vehicle required to be registered hereunder shall be attached to the rear of the vehicle. The registration plate issued for a truck tractor shall be attached to the front of the truck tractor. The special plate issued to a dealer shall be attached on the rear of the vehicle when operated on the highways of this state. Registration plates issued for a motor vehicle which is model year 1948 or older, and reconstructed or specially constructed vehicles built to resemble a model year 1948 vehicle or older, other than a truck registered for more than five tons, motorcycle, or truck tractor, may display one registration plate on the rear of the vehicle if the other registration plate issued to the vehicle is carried in the vehicle at all times when the vehicle is operated on a public highway. It is unlawful for the owner of a vehicle to place any frame around or over the registration plate which does not permit full view of all numerals and letters printed on the registration plate.

321.38Plates, method of attaching--imitations prohibited. Every registration plate shall at all times be securely fastened in a horizontal position to the vehicle for which it is issued so as to prevent the plate from swinging and at a height of not less than twelve inches from the ground, measuring from the bottom of the plate, in a place and position to be clearly visible and shall be maintained free from foreign materials and in a condition to be clearly legible. An imitation plate or plates imitating or purporting to imitate the official registration plate of any other state or territory of the United States or of any foreign government shall not be fastened to the vehicle.

321.388Illuminating plates. Either the rear lamp or a separate lamp shall be so constructed and placed as to illuminate with a white light the rear registration plate and render it clearly legible from a distance of fifty feet to the rear. When the rear registration plate is illuminated by an electric lamp other than the required rear lamp, the two lamps shall be turned on or off only by the same control switch at all times when head lamps are lighted.