Eliminate bait cars!!
I often see vehicles that don't really exist. You ask the dealership about it,
and it "just sold" or it's a "demo" model.
One clue is how long it has been listed. Any popular vehicle that lasts more
than a month at a dealer is not likely real, and many of the ones I have seen
have supposedly been listed for 2 or more YEARS: these are not real and
should be forced to be taken down.