Honest John's Used Car Lot, Los Angeles CA, 1947
This article points out that used car dealers were selling new cars at high prices in the late '40s. New cars were in short supply and hard to get right after the end of World War II. A "black market" existed, in which used car dealers (and most new car dealers) bought and re-sold new cars at prices up to 50% higher than a customer would usually pay for such a car. There were no "Monroney" new car stickers until January 1959.