In the 1971 Turin Motor Show, the Maserati Boomerang debuted as a mock-up concept with no engine or running gear, but that didn't matter to the lucky few who laid eyes on its glorious, futuristic design. A year later, at the Swiss Auto Show, it had all the elements of a roadgoing car, including a V8 engine, a working gearbox, and a space-age interior.

Designed by the legendary Giurgetto Giugiaro and built by Italdesign, the Boomerang had a race-bred 4.7-liter V8 engine that Maserati claimed could reach 186 mph top speed. The concept car’s biggest draw, however, was the way it looked: an almost-flat windscreen, a panoramic roof, retractable square headlamps, and horizontal taillights.

Maserati sold its only Boomerang to a Spanish car collector in the mid-'70s, and since then, the car has traded hands several more times. In the most recent handoff, on September 9, 2015, the car sold at a Bonhams auction at the Château de Chantilly for a staggering $3.7 million — an excessive sum perhaps, but the Boomerang is genuinely one of a kind.