This is the Only Factory Convertible 1967 Shelby GT 500 Mustang

In late 1966, three brand-new Mustangs sat finished in Shelby American’s Los Angeles shop, all painted Candyapple Red: a coupe, a fastback, and a convertible. Two became the template for a production run. The third never did, because Ford shelved the convertible GT500 for a year, leaving exactly one 1967 example in existence — and Carroll Shelby kept it for himself. Read on to find out what happened to serial number 0139.

Three cars finished at roughly the same time, in the same shop, in the same color, built to the same specification. Two of them went on to define an entire model year, becoming the first production examples of one of the most recognizable performance cars America ever built. The third sat there as a plan quietly changed around it, and in doing so became something neither of its siblings could ever be: the only one. That car — a Candyapple Red 1967 Shelby GT500 convertible — has spent the last five decades as the answer to a trivia question most people do not know exists. The story of how it stayed unique is better than the trivia.

Serial Number 0139 and What Makes It Singular

The car carries Shelby sequence number 0139, and it is the only 1967 GT500 convertible ever produced. That distinction is absolute rather than approximate; there is no second example, no disputed claimant, no gray-market conversion with a good story attached. It was built alongside a coupe and a fastback as one of the first production GT500s to come off the line, with the coupe and fastback completed first and the convertible following roughly two weeks later, in November 1966. All three wore the same paint and shared essentially identical equipment, which makes the divergence in their fates that much starker.

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The 428 Police Interceptor and Its Dual Quads

Under the hood sat the 428-cubic-inch V8 that gave the GT500 its identity, in Police Interceptor specification with dual four-barrel carburetors on an aluminum medium-riser intake. Ford rated it at 355 horsepower, a figure most people in the industry regarded then and regard now as conservative, and paired it with substantial torque delivered low in the rev range. The GT500 was a fundamentally different proposition from the small-block GT350 that shared the showroom: less interested in cornering balance, far more interested in what happens when a long, straight road opens up in front of it.

Loaded Like a Personal Car, Not a Race Car

The equipment list reads like a car specified by somebody who intended to actually use it. This convertible was built with a C6 automatic transmission, air conditioning, power steering, power brakes, tinted glass, and a black interior. That is a comfort-oriented combination, not a track specification, and it says a great deal about the car’s intended role. A four-speed manual would have been the enthusiast’s choice; an automatic with air conditioning in Southern California is the choice of someone who plans to drive the car to meetings, hand the keys to visiting executives, and not think about it much in between.

Why Ford Shelved the Convertible for a Year

Ford’s decision to shelve the convertible GT500 for the 1967 model year was a straightforward product-planning call rather than an engineering problem. The 1967 Shelby program was already a significant undertaking, with the extensive fiberglass bodywork, revised lighting, and the addition of the big-block GT500 to a lineup that had previously been small-block only. Adding a convertible variant meant additional structural work, additional certification, and additional complexity on a program that was already stretched. The convertible arrived the following year instead, which left this single completed example stranded outside the production run.

Carroll Shelby’s Company Car

Rather than being scrapped or converted, the car was retained as an engineering prototype and company vehicle, and Carroll Shelby assigned it to himself. For roughly four months it functioned as an ordinary shop car: loaned to friends, driven by employees, handed to visiting Ford executives who wanted to experience what the new program felt like. That is the detail that makes the story worth telling. The only 1967 GT500 convertible in existence spent its first months being used casually by people who had no idea they were driving a car that would never have a counterpart.

The 1968 Convertibles That Followed

The convertible GT500 did reach production for 1968, when Shelby’s lineup was restructured and open-top versions of both the GT350 and GT500 became available to buyers. Those cars were built in meaningful numbers and remain highly desirable, but they are a different proposition entirely: production cars from a catalogued model year, with siblings, with comparable sales, with an established market. The 1967 car’s value rests on the opposite quality. It cannot be compared to another example because there is no other example, and in the collector world that is a rare and awkward position for a car to occupy.

How a One-Off Survives Fifty Years

Survival is the underrated part of this story. A one-off prototype in the late 1960s had no particular protection. It was a used car with an unusual history at a time when Shelby Mustangs were simply fast used cars depreciating like everything else, and plenty of significant vehicles from that era were wrecked, parted out, repainted, or modified beyond recognition during the decades when nobody was watching. The reason this car exists today in identifiable form is a chain of owners who happened to understand what they had, which is far more luck than any of us would like to admit.

Documentation Is the Whole Ballgame

For a car like this, documentation is not supporting evidence — it is the asset. Shelby American Automobile Club registry records, factory build documentation, invoices, and period photographs are what separate a genuine one-off from a very convincing story. That matters more here than on almost any other car, because the claim being made is exclusive by definition and therefore attracts scrutiny. A well-documented Shelby with an unbroken paper trail sits in a completely different market position from an identical-looking car whose history has a gap in it, and no amount of restoration quality closes that gap.

What a Genuinely Unique Car Is Worth

Which raises the question of what a genuinely unique car is actually worth, and the honest answer is that nobody knows until it sells. Ordinary valuation works by comparison: find recent sales of similar cars, adjust for condition and options, and arrive at a number. That method collapses entirely when the population is one. What is left is a negotiation between a seller who knows there is no substitute and a buyer who knows there will never be another chance, which is exactly the situation that produces the headline results the collector market is famous for. Serial 0139 is one of the few cars where that framing is literally accurate.

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