General Motors kept an early prototype of the midengine Chevrolet Corvette under wraps by disguising it as an Australian utility vehicle.
GM engineers hid the Corvette C8's chassis and suspension in the body of a Holden Ute, which has a pickup-style flatbed. They gave it the code-name Blackjack.
Engineers considered using mules that looked like station wagons or small vans but decided the Ute hid the midengine layout best. They affectionately called it the "clown suit" over the body structure, said Mike Petrucci, the C8's lead development engineer.
GM built the car at its technical center in Warren, Mich., in 2014 and tested it at its proving grounds near the village of Milford.
Some spy photographers hired helicopters to fly over the proving grounds to spot the mule, according to the Detroit Free Press. By then, Blackjack had been replaced by 11 other disguised mules that looked more like the finished product.
To keep those cars from being photographed, test drivers kept a fabric car cover with them and opened the windows slightly. At the first sound of a helicopter, they pulled over to quickly hide the car underneath.
No aerial photographers ever spotted one of the mules out in the open, the newspaper said, but they did pass over the engineers waving next to a covered Corvette at least a dozen times.