The applicable North Carolina state statute says that "For an out-of-state vehicle that is 1980 model year or older, this inspection shall consist of verifying the public vehicle identification number to ensure that it matches the vehicle and ownership documents." Inspectors have interpreted "public vehicle identification number" to mean the VIN plate, and if that is missing they do not have to try to find another place where the VIN might be. Obviously, for any given old car the alternate location of the VIN could be anywhere and time-consuming to find. Some inspectors I have dealt with are willing to recognize the VIN other than on a factory-issued VIN plate if they are shown where it is, and it is permanently marked. Others simply interpret the statute to mean "if the VIN plate is missing, or if it is obviously not factory original" that's enough to assign a DMV VIN. I have worked with the various state DMVs (and foreign registration authorities) on seven or eight occasions for Austin-Healeys with missing or reproduction VIN plates to have the original VIN officially recognized. Some are easy, others are very difficult.