This one is one of the most interesting Mustang prototypes. Even though it didn’t appear on the show circuit in the late â60s, it caused a lot of controversies. Basically, this is the 1969 Boss 429 with the engine in the trunk. Ford did some extensive testing to see if this conversion had significant advantages over the standard layout. They placed the engine longitudinally in the trunk and connected it to the rear wheels over the C6 automatic transmission unit.
Ford turned the rear glass window into a hatchback door to have access to the engine. And in fact, the whole conversion was surprisingly trouble-free. This Boss 429 had a 40/60 weight balance. So, the added weight over the rear axle helped launch it off the line while reducing the wheel spin. However, Ford realized there weren’t any significant performance improvements, so they decided to kill the project.
In the late ’60s, Ford had several successful performance editions of the Mustang. But even so, Shelby developed a few of his own prototypes to further explore the limits of the platform. Ford named it the Quarter Horse, building the pre-production prototypes in 1969 with lots of interesting design cues they linked to the Shelby and Boss Mustangs.
Those cars had a Shelby front end with a Mustang rear end. Ford added a Boss 429 engine and a Mercury Cougar dashboard. Their idea was to produce a more affordable Shelby GT 500. However, Ford killed the project in 1970.
In 1976, Ford decided to play around with the idea of a Mustang wagon. They decided to base it on the Mustang II platform and equip it with a roof rack and woodgrain inserts on the sides. In those days, Chevrolet had the Vega three-door station wagon on offer, so Ford wanted to compete in that market segment, as well.
However, Mustang fans are grateful that this car never went beyond the concept stage. After all, a Mustang station wagon with wood grain in the typical â70s fashion would’ve killed any sporty characteristics this model barely even had. The Mustang II had almost destroyed the Mustang’s reputation from the ’60s, so a wagon version would have killed it for good.
Briefly, in 1979, it looked like Ford would produce an interesting looking Mustang as a homologation special for rally racing. Over the years, Mustang was a drag racer, street racer, circuit racer and even entered the Le Mans, but it was never a successful rally car. However, with the Mustang RSX, Ford wanted to change all that.
Although the car had a stock 2.3-liter engine, Ford was working on turbocharging it. The public was interested, so the RSX concept gained much coverage from period magazines and fans. But eventually, Ford decided to drop it.
Ford built this interesting car with the help of the well-known McLaren racing team via their American operation office in Michigan. The whole idea behind the project was to take a 2.3-liter turbo engine from the regular Mustang and transform it into a street racing beast. They planned to add a race-tuned suspension, lightweight body, and a host of other modifications. So, McLaren and Ford installed a tuned turbo engine pumping out 190 HP, which may not sound like much nowadays.
That was a big number for the day, especially coming from 2.3-liters, totally changing the looks of the Fox Mustang. The result was an impressive performance and driving dynamics but also a high price tag. Ford offered it for sale at the price of $25,000. And that was roughly three times the price of a regular example. So, despite all the interesting features in the M81, it was a tough seller. In fact, Ford only sold approximately 10 before canceling the project.
By the late ’80s, Ford decided to kill the Mustang as a rear-wheel-drive car. They wanted to introduce the Mustang name on the smaller, more economical front-wheel-drive platform from Mazda. They made the decision, to their designer teams already started working on the possible design.
Fortunately, under severe public pressure, Ford decided to cancel the project. They realized it was a better idea to return the Mustang to its roots. So, they went for a new design and technology, canceling the FWD Mustang project. And this is how the 1989 Mustang FWD may have looked if Ford had followed through with their plans.
The Mustang Boss Concept from 1995 was one of the craziest machines Ford ever produced under the Mustang name. It had a Boss 429 motor from the late ’60s. But they bored and stroked to almost 10-liters of displacement and with 855 HP on tap. The results were astonishing.
The red Boss 10.0-l could accelerate from 0 to 60 mph in just 1.9 seconds. However, despite the enormous interest from fans who wanted to purchase this crazy machine, Ford only produced one of them.
To show the potential of their fourth-generation Mustang, Ford presented the Super Stallion concept in 1997. The car was a regular GT, but they equipped it with a modified engine that could run on alcohol. Amazingly, it produced 545 HP with the help of its twin turbochargers.
Ford said they would consider the future production of alcohol-powered engines as an answer to the potential oil crisis. But, as you probably know, they soon abandoned the Super Stallion project.
In 1999, Ford debuted the FR500. But from the outside, this Mustang looked like an ordinary ’99 coupe with just a bit different front fascia. However, the FR500 was a thoroughly modified car using Ford Performance parts and expertise. So, it was significantly more powerful at 415 HP.
Also, it had a different suspension, a bigger wheelbase, and better weight distribution. In fact, the FR500 rode much better and was capable of higher cornering speeds. But for some reason, Ford decided to shelve this project and not offer it to the public.
In 2004 all eyes were on Ford and their Mustang concept cars after they announced the fifth, retro-futuristic generation of the Mustang. However, soon Ford presented the GT-R. It was even more interesting since it was a full-fledged racing car. In the early 2000s, Ford wanted to restore its reputation for racing.
The GT-R looked like the best way to produce a factory race car to enter into various championships. But despite the fact the GT-R was a fully functional car that sparked a lot of interest from racing teams, Ford decided to go a different route.
Italdesign, one of the world’s most respected design houses, teamed up with Ford in 2006 to present the gorgeous Mustang Giugiaro. But it wasn’t just a styling exercise for the Italians. It was a fully re-bodied car with a 4.6-liter V8 and a supercharger. It produced 500 HP and was faster than the regular model. Better still, it was more luxurious and lighter. Italdesign even revealed its plans for a limited production run of those machines. Of course, it would come at a higher price since they aimed for more discriminating buyers. Unfortunately, this gorgeous car never happened.
These are the 20 Ford Mustang prototypes that almost made it into production. Who knows, maybe Ford will decide to resurrect some of these someday. If they do, which one would you choose? All of these projects had promise, so there’s a chance Ford will decide to go with one of them in the future.