At the end of the 1970’s, American automakers were faced with huge changes in the cars they made and sold. Fuel efficiency was at the forefront of most car buyers minds, though Americans still wanted rear-wheel drive and horsepower. That left companies like Ford with a conundrum. How do we offer Americans an attractive, fuel efficient, yet powerful automobile?

The answer Ford came up with was the 1979 Probe 1 Concept. Designed to eventually replace the Mustang…it never did. But Hemmings Auto Blog reports that this one-of-a-kind concept is up for sale, again.

The first concept was built and designed by coach-maker Ghia, who wanted to explore the limits of aerodynamic efficiency. Namely, they wanted to see how smooth a car they could make, without it looking unbearably ugly. In all, five Probe concepts were made, all of them looking not unlike spaceships. Ghia managed to achieve a drag coefficient of 0.22, which is amazing. Even cars like the Toyota Prius only have a drag coefficient of 0.27 or so. Then again, one look at the Probe and you know why.

Interestingly enough, Ghia built the Probe concept on the Fox body platform…the same platform that underpins 1979-1993 Mustangs. That means that this concept is rear-wheel drive. Another interesting tidbit is the drivetrain, a 2.3 liter turbocharged 4-banger found in the ’79 Mustang Cobras. Ultimately, America would dismiss these turbocharged engines in favor of a return to large displacement V8’s, but the Probe concept is an important part of Mustang history…if only to remind us of what we avoided.