Legal Question in Traffic Law in Iowa

As long as it is mounted on the rear of the vehicle, I think so. Section 321.37 covers display of plates and here's what it says.

321.37 Display of plates.

1. 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.

2. 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.

3. 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.