They call anyone with a car advertised to sell an ad in their magazine.  They don't identify their purpose until you've confirmed that you still have a car for sale.

Got call from 702-567-8819 from "Brian" asking about the car we had listed for sale.  Was told to call 866-318-9495.  After calling that number, got a voice mail which said he was "Audi(?) from One Stop Motors.

one stop motors said i had a car listed on auto trader and they wanted information