When it comes to collector cars, exclusivity is king, which is why low (or numerically significant) serial numbers are so desirable.

Still, a production car is a production car, and there are often thousands of other examples that differ only by VIN.

Pre-production cars, such as those built to test the durability of a new model, are a different story. Generally speaking, only a handful get built, and most go to the crusher afterwards.

Since they’re not built to the same standards as production cars, and may lack things like advanced airbags, pre-production cars (usually) can’t be titled and licensed for street use. Like concept cars, their value comes from their rarity.

As for the 2013 Ford Mustang Shelby GT500, you won’t find a more exclusive example than a pre-production “durability car” driven by none other than Carroll Shelby himself. As Mustangs Daily explains, this car will be auctioned off for charity at the upcoming Barrett-Jackson Scottsdale auction.

Since it’s a pre-production model, the car will be sold on a bill of sale only and can’t be licensed for street use. That doesn’t matter to the Shelby American Registry, since the organization will still list the historically significant development car in its database.

Designed and engineered by Ford’s SVT group

, the car was hand built and driven at Sebring, Ford’s Arizona Proving Grounds, the Route 66 road course and other facilities, with many of the car’s miles racked up by its namesake.

Proceeds from the sale will go to support the Juvenile Diabetes Research Foundation, so feel free to bid generously on lot number 3043, set to be hammered off on January 21 at 8:30 pm. You’ll be buying an ultra-rare piece of Shelby history that just happens to double as the ultimate track-day toy, all while supporting a worthy cause.