The Ford Mustang has enjoyed a long career as America's pony car since it debuted in 1964. It lived through the Malaise era, took on competition from all manner of American rivals, and even went on to find considerable success in other markets – no easy feat for a muscle car.

Through those years, we've been blessed with a total of seven Mustang generations, but we shouldn't pretend each one was as brilliant as the next. While the first-gen model has gone down as an important slice of American motoring history, the Mustang II that followed is largely best left forgotten.

However, the third generation, known as the Fox Body Mustang, rescued the Mustang's reputation as a muscle car and stood the test of time.

These cars debuted as '79 model years, and were not replaced until the SN95 cars marched onto the scene for 1994. Throughout those years, an estimated 2.6 million Fox Body Mustangs found owners, making it by far one of the most successful Mustang generations.

Among them, though, were some exceedingly rare variants, such as the immensely sought-after 1-of-107 SVT Cobra R, and the 3,003 Feature Cars of '93, and the 1985 Twister II Mustang.

These Mustangs, along with quite a few others that are rarer than many multi-million-dollar super- and hypercars, stand as the rarest Fox Body cars ever produced. Starting with the more common and leaving the rarest for last, here are seven Fox Body Mustang variants with seriously scant production numbers, and how much they're worth today.

If we were to split the Turbo GT up by model year, the '83 Mustang Turbo GT would sit much farther up this list, since only 556 examples made it out of the factory gates. However, with 3,972 examples produced the following year — split between 3,241 hatchbacks and 731 convertibles – the total Turbo GT production comes out to 4,528 examples.

As the name suggests, instead of relying on old-school six- or eight-cylinder lumps that traditionally featured in Mustangs, the Turbo GT took advantage of boost. Under its hood sat a fuel-injected and turbocharged 2.3-liter inline-4, and when fed the correct premium gas, it was good for 145 horsepower and 180 pound-feet of torque.

It was actually quite a technically impressive mill for the time, sporting forged aluminum pistons, a lightweight flywheel, valves with a higher heat resistance, and extra oil cooling hardware — this was certainly no half-measure attempt from the Blue Oval engineers.

Ford sadly canned the Turbo GT after the '84 model year. While a smaller four-cylinder engine was no doubt more economical than a naturally aspirated V8, and yet still punchy enough to induce a smile on the face of most drivers, less than 5,000 sales across both model years clearly meant it wasn't a great car to market to the mass market.

Such scarcity has not translated into high desirability in the modern day, either, since any recent sales we found on Bring a Trailer barely scraped past $12,000.

The 1992 Ford Mustang Summer Edition, or, to call it by its full name, the 1992 Vibrant Red Mustang LX 5.0 Limited Edition Convertible, was exactly that — a vibrant red drop-top 'Stang. It was powered by a 225-hp, 300-lb-ft, 302-cubic-inch High Output (H.O.) V8, and it debuted halfway through the 1992 model year during the — you guessed it — summer.

Other unique features include a white leather interior with contrasting black stitch-work and a complementary white fabric roof. It was by no means subtle, especially with 16-inch Opal Pearlescent white wheels completing the bold look.

Also helping the Summer Edition Mustang differentiate itself from similarly specified but otherwise completely regular Mustangs was a unique decklid spoiler, body-colored mirrors, plus a variety of other Vibrant Red exterior trims too.

Ford churned out just 2,193 of these striking convertibles, and of those, the manual-equipped cars are by far the rarest. Buyers had the choice of a four-speed automatic or five-speed manual, and only 787 of them chose the three-pedal version.

Today, the Summer Edition is quite a desirable little classic, and although it doesn't exactly command huge premiums, the finest examples are starting to require larger investments when they do change hands.

For example, recent online auction results courtesy of Bring a Trailer reveal that smart, low-mileage cars sell for in excess of $20,000 fairly regularly, while the very best of the bunch can sometimes see the hammer fall at double this price.

Much like the aforementioned 1992 Summer Edition, Ford offered a pair of other such special editions in the following year. These colorful special editions are sometimes called "Feature Cars," and for '93, Vibrant Red stepped aside for Vibrant White and Canary Yellow. Their features were really quite similar to the '92 car, with a 205-hp 5.0-liter V8 providing propulsion, and a smattering of white visual details.

Once again, they were all LX-based convertible cars.

In total, Ford produced 3,003 of these 1993 Feature Cars, which, of course, makes them less rare than the aforementioned '92 Vibrant Red model. However, if we break production down by color, we find 1,503 Canary Yellow examples, and 1,500 in Vibrant White, so the individual models are actually rarer than the special edition of the previous year.

We also find that, again, those equipped with the five-speed manual are rarest, with an estimated 565 yellow manuals, of which only 113 sported the white interior and top combination. As for the Vibrant…