As I recall the story...
Shelby registered a bunch of VIN numbers during 1966 for Shelby Cobras. The car was based on an AC Ace, but since this was to be a US built car it had to have a US VIN number and what not. He registered more VIN's than he ever built cars.
And then some sharp lawyer pointed out that 1966 Cobras were going for big $$$ and that Shelby could finished the 1966 run with the VIN numbers he had. Somehow the DOT gave him a pass on all of this, likely because he was Carroll Shelby and the number of cars would only be about 100 total.
I think the new price was $500,000 or so, but I could be wrong.
Anyway.... There is one coming up for auction via
Government Surplus Auctions at Government Liquidation.
427 Shelby Cobra Roadster - Government Liquidation
Check it out.... and feel free to fill in any blanks in my description.