The Unicorns Of The Mustang World
Every Mustang tells a story, but some were so rare that they were never part of the public tale. Built in secret, sold in handfuls, or reserved for the racetrack, these were more than cars: they were icons in Mustang's long-standing legacy as one of the greatest car models of all time. Here are 20 examples that remain nearly impossible to spot by chance.
1. 1967 Shelby GT500 Super Snake
The 1967 Shelby GT500 was commissioned as a tire test vehicle and was fitted with a 427-cubic-inch GT40 engine. It clocked 170 mph during testing and was deemed too expensive for mass production. The only unit produced was sold at auction for over $2 million.
Revology Car Review | 1967 Shelby GT500 Super Snake in Dark Blue Metallic by Revology Cars
2. 1964 Mustang III Factory Prototype
Unlike anything that followed, the Mustang III was a sleek, two-seater concept convertible. The car featured a chopped-down body and an aircraft-style instrument cluster. Just one prototype was built, making public appearances in the mid-‘60s before vanishing into private hands.
3. 1968 Shelby EXP 500 “Green Hornet”
Ford scrapped most prototypes, but this one survived. A testbed for experimental Shelby features, the “Green Hornet” included an independent rear suspension and fuel injection, far ahead of its time. Its 2013 auction value was estimated at $2–3 million, though it didn’t sell.
THE GREEN HORNET - 1968 Shelby Mustang EXP-500 Prototype - BARRETT-JACKSON by
4. 1965 Shelby GT350 “Drag Unit” Prototype
This Shelby prototype came factory-equipped with slicks, a special drag-tuned 289 Hi-Po V8, and unique suspension geometry. Unlike other GT350s, it was not homologated for SCCA racing. Only one unit is known to exist today, and it's locked away in private ownership.
5. 1970 Mustang Quarter Horse
Only two were built—one automatic, one manual. Both were painted Grabber Green and equipped with Boss 429 engines and Lincoln interiors. A rare fusion of Boss 429 engineering and Cougar styling cues, the Quarter Horse was a secret Ford styling and performance experiment.
6. 1965 Shelby GT350R Prototype “Flying Mustang”
Known as the very first GT350R, this prototype was piloted by Ken Miles in its racing debut. During the outing, it caught air at Green Valley Raceway, earning the nickname “Flying Mustang.” It sold for a staggering $3.85 million in 2020.
Ken Miles Driven 1965 Shelby GT350R Prototype // Mecum Indy 2020 by Mecum Auctions
7. 1971 Mustang Mach 1 Twister Special
Only 96 of these tornado-themed Mustangs were built for Kansas dealerships as part of a regional promotion. They featured unique “Twister Special” decals and performance upgrades from the 429 Super Cobra Jet package. Surviving examples are scarce and command premium prices.
1970 Ford Mustang Twister Special by American Muscle Car Museum
8. 1980 McLaren M81 Mustang
The M81 was built to revive Mustang’s performance image. A limited collaboration between McLaren and Ford, just 10 were produced, each hand-built with custom turbocharged engines and distinctive orange paint. One remains in Ford’s private collection, while the others have largely disappeared into obscurity.
2020 SCOTTSDALE - Lot #771 - 1980 Ford Mustang McLaren M81 by Barrett-Jackson
9. 1966 Ford Mustang GT K-Code Convertible
Few Mustangs came factory-equipped with the high-revving K-Code 289 engine, and even fewer were convertibles. The number of units made in this specific configuration ranges between 50 and 100. With a lightweight build and performance orientation, the K-Code Convertible now commands six figures at auction.
10. 2000 SVT Cobra R
This track-focused beast came without a backseat, radio, or air conditioning. Ford built only 300 units, each powered by a hand-assembled 5.4L V8 pushing 385 horsepower. Designed strictly for racing enthusiasts, chassis number 001 is preserved in the SVT archives.
11. 1965 Mustang Station Wagon Prototype
Italian coachbuilder Intermeccanica built a prototype Mustang wagon at the request of a U.S. magazine. With its elongated roofline and custom rear glass, it blended sports car styling with utility. The original car still exists but remains hidden in a private collection.
12. 2008 Mustang FR500CJ “Cobra Jet”
Built for drag racing, this factory race car wasn’t street-legal and came stripped of unnecessary weight. Ford produced only 50 units to honor the original 1968 Cobra Jet. Serial numbers were assigned through Ford’s Racing division, and many went straight to competition teams.
2008 Ford Mustang Cobra Jet - FR500CJ (4/3/13 at Barrett Jackson Palm Beach FL) by bbossingg
13. 1967 Shelby GT500 Convertible Prototype
Although Shelby never officially offered a GT500 convertible in 1967, a single prototype was created for evaluation. It packed the same 428 Police Interceptor V8 and carried Shelby badging throughout. Today, this one-of-a-kind convertible model resides in a private museum.
IN-DEPTH - 1967 Shelby GT500 Prototype “Little Red” - BARRETT-JACKSON by Barrett-Jackson
14. 1995 Mustang SVT Cobra R
Just 250 units of the 1995 Cobra R were built, each featuring a 351 Windsor V8 and no rear seats. This car was the most powerful Mustang available that year. Ford required buyers to show a valid racing license or proof of competition use.
Myself (Adrian Pingstone). on Wikimedia
15. 1966 Mustang GT Convertible With Bench Seat
This configuration was so uncommon that only a few units are documented today. The combination of GT trim and a factory front bench seat was nearly unheard of. The car retained GT essentials like dual exhausts with chrome tips.
16. 1964 World’s Fair Skyway Mustang
Unlike production Mustangs, this model was built specifically for Ford’s “Magic Skyway” ride at the 1964 New York World’s Fair. Roughly a dozen were modified to run along tracks. Few were returned to Ford, and only a handful have ever resurfaced.
Mustang #4 at 1964 NY World's Fair by NewCarNews.TV
17. 1993 Mustang SVT Cobra R Prototype #R007
Before full production of the ‘93 Cobra R began, a few pre-production cars were built. Chassis #R007 was one such prototype, differing slightly in specs from the final 107 units produced. The vehicle was never publicly sold and remains in Ford’s archives.
InSapphoWeTrust from Los Angeles, California, USA on Wikimedia
18. 1968 Mustang California Special (GT/CS) High Country Edition
While the California Special is rare, less than 250 units were sent to Colorado as “High Country Specials.” These combined GT/CS styling with special badging and high-altitude tuning. As of now, only a handful of examples remain, making them among the rarest regional Mustangs.
Greg Gjerdingen from Willmar, USA on Wikimedia
19. 1972 Mustang Sprint USA Edition Fastback
Produced in 1972 to celebrate the Olympics and American patriotism, the Sprint USA package featured a red, white, and blue exterior theme. While more common on coupes, the fastback Sprint versions are extremely scarce. Fewer than 50 are estimated to exist today in original condition.
20. 1965 Mustang GT Export Model (Right-Hand Drive)
Ford built a limited number of right-hand drive GT models for export to countries like Australia and the U.K. These cars included metric instrumentation and local compliance changes. Authentic examples are rarely found outside of auctions or museums.
