Two evergreen schemes in the used-vehicle market, and the checks that defeat them. Curbstoning — unlicensed dealers posing as private sellers: check whether the seller's name matches the title, and search the phone number for multiple concurrent listings. Title washing — moving a branded title through states until the brand drops off: run the VIN through a national history database, which preserves brand history across state lines even when a current paper title looks clean. Both checks take minutes; both are cheaper than the alternative.