OLD CALIFORNIA LICENCE PLATES

Black on yellow, yellow on black, or yellow on blue? There is a market, but ONLY for matched pairs. A single plate you might as well patch a floorboard with it.
California is now allowing the use of old plates again, but since they require front and rear plates, pairs are neccessary. (Oh and by the way, california dealer license plate frames have value too. I would love to get a Clay Chevrolet frame for the 55 chevy my folks bought new, that i still have.)