out-of-prefecture license plate
Refers to a vehicle license plate issued in a prefecture other than the one where the vehicle is currently located or observed. Commonly used in traffic reports, local news, and everyday conversation when noticing a car from another area.
Many cars with out-of-prefecture license plates are parked at the tourist spot.
A truck with an out-of-prefecture license plate caused an accident.
Compound of 県外 (outside the prefecture) and ナンバー (number, short for ナンバープレート, license plate).