As the GNXs continue to rise in value, I have no doubt that authenticating a "real" car and what constitutes a "real" car will become more and more difficult. Cars that were wrecked and/or abandoned years ago will be "resurrected" or cloned. Just look at how many cloned Hemi Cudas, '69 z28 Camaros, and GTO Judge RA IV cars are out there now. Technology has enabled dishonest sellers to create very authentic paperwork and VINs that probably could fool all but the most astute collectors. Would a formerlly wrecked GNX that was rebodied with a GN, or even a regular Regal tub still be considered a "real" car?
Although I am dubious of the documented existence of GNX 548, it is not my intent to infer that the car listed here isn't genuine nor am I out to insult the OP. I just feel that this car raises some considerations in the greater scheme of things.