A history check may show it is legit, doesn't mean it is.

Basically, as an example, a fiesta is damaged in a crash, but insurance is not notified and it is not written off. Instead of the car going straight to the scrap yard, another good fiesta is stolen, (yours), and the ID from the crashed one is put in to the good one.

The crashed car is then crushed, hiding all evidence of it, and the owner is now selling a stolen car with the ID from his old crashed one that has since been disposed of.