Among Mustang fans, there are some cars that have reached “legendary” status. Cars that were race cars, rare option configurations, or just cars with a unique history and some serious star power to go with it. Among these is the “Green Hornet,” part concept car, part experimental Shelby, all badass. 

Yet this is one of those cars whose owner had no idea what they had. The L.A. Times reports that after an unlikely discovery by a Ford executive’s son, this now-restored concept/test vehicle is heading to auction…and could fetch up to $2 million.

As legend has it, this 1968 Mustang started out as a coupe-style concept car from Ford itself. Painted in “Lime Gold “, outfitted with a 390 cubic-inch big block V8, and given a stronger automatic transmission borrowed from Lincoln, it was a pretty gnarly machine.

Yet it wasn’t gnarly enough for Ford to bring this “GT/Sport Coupe” to production, so instead they sent it off to Carroll Shelby. There, the car underwent a sort of transformation, utilizing a number of experimental technologies that included fuel injection, independent rear-suspension (something even modern Mustangs still don’t have) and…wait for it…a power radio antenna. Boom!

Shelby called the modified Mustang the “EXP 500” and painted it the deep green you see today. When Shelby was done with it though, they sent it to a Ford scrap yard to be crushed. But in swept the father of current owner Randy Darrow, who bought the car off the lot and drove it as a daily driver.

Years later, Randy saw an article about the car, verified its authenticity, and had it restored. When it heads to the auction block in January of next year, preliminary estimates put the price at or around $2 million. That’s what we call an awesome investment.