When someone sells you a vehicle, but refuses to provide you with the documentation
necessary to register the vehicle.
This term comes from a notorious
Missouri car dealer who sold tens of
people automobiles but refused to give them the titles because he used them as collateral to secure personal loans.
The
guy I bought my
truck from really Carmack’ed me! He refuses to send me a
bill of sale, and the DMV won’t let me register the truck in my name without it.