Most concept cars from a SEMA stand quietly disappear. This one didn't. Unveiled at the 2009 SEMA Show in Las Vegas, the Shelby Turbo was a prototype, dealer-installed package developed with Turbonetics to wring 550 horsepower from the 4.6-liter V8 in 2005–2009 Mustang GTs. What set it apart from Shelby's existing supercharger kit was the goal of full 50-state and CARB emissions compliance, making it a rare attempt at a forced-induction Mustang you could buy and register anywhere.The deep-draw hood wears bold Shelby Turbo cobra graphics. Photo via Hagerty Marketplace.The package never went into series production, but the actual SEMA show car survived. After its debut, it was tested at Las Vegas Motor Speedway by Shelby American engineers and the media, and email correspondence between the selling dealer and Shelby American in 2022 backs up its one-of-one status. There's even documentation of the car alongside Carroll Shelby at the 2009 show.Finished in Performance White with bold Shelby Turbo decals over a Dark Charcoal cloth interior, the car wears the full prototype spec: the Turbonetics turbocharger and intercooler, a Shelby Pro Plus brake system with Baer six-piston front calipers, performance suspension with caster/camber plates, a Borla exhaust, short-throw shifter, 18-inch chrome wheels, a deep-draw pinned hood, and serialized dashboard and engine-bay plaques. It shows roughly 12,700 miles.Inside, the Dark Charcoal cloth cabin adds Shelby gauges atop the dash and a short-throw shifter. Photo via Hagerty Marketplace.The documentation file is thick for a car this age: a Ford window sticker, a Deluxe Marti Report, a Shelby Vehicle Authenticity Certificate, Shelby memorabilia, a clean CARFAX, and a clean Louisiana title in the seller's name. For context, the seller notes the same car previously sold at a Barrett-Jackson event years ago.AdvertisementAdvertisementListed out of Covington, Louisiana, the one-off Shelby Turbo had climbed to $45,000 on Hagerty Marketplace as bidding heated up. For a documented, drive-it-anywhere piece of Shelby prototype history with five-figure mileage, it's an unusual chance to own something that was meant to preview the future and instead became a single, surviving artifact.See it here on Hagerty Marketplace.⚡️ Read the full article on MotoriousSign up for the Motorious Newsletter. For the latest news, follow us on Facebook, Twitter, and Instagram.