Steve's high end car stealing ring is very much out of place in the U.S. version of the series. The reason it works in the original UK series is because it is an actual problem for high end car owners over there, cars are often professionally stolen, but immediately loaded on containers for shipment to Eastern Europe and Russia making recovery before export very difficult. In the U.S. though the amount of cars being stolen would immediately be noticed, also the cars shown thus far would have to be serviced and repaired by Steve's crew if we are to assume they are selling within the U.S. and have the means to disable tracking equipment within the cars. The reason the cars can't go to the dealer or be chopped up and have their parts used on other cars is because any part that is even slightly electronic will be tagged electronically with the single VIN the part will work with (i.e. a motorized side mirror tagged for VIN-X would not work with a car whose VIN is Z). The reason we assume Steve is selling within the U.S. is because he has his shop working on the cars which is completely unecessary if he's exporting - also driving them around is ill advised given he's in Chicago a place that is not dense enough with those specific cars to make him inconspicuos enough to drive around without worries (the BMW and Lexus being the 2 exceptions).