The TVR Cerbera Speed 12 was an ultra-high performance concept car from the late 1990s, initially designed for GT1 racing to challenge the McLaren F1. It featured an extreme 7.7-liter V12 engine, which was so potent it reportedly broke the dynamometer during testing, with power estimates nearing 1,000 horsepower. Weighing just over 2,200 pounds, it was projected to hit 60 mph in 2.9 seconds with a top speed over 240 mph. Ultimately, TVR's owner, Peter Wheeler, canceled the planned production, declaring the single finished prototype too savage and unusable for public roads. Only one road-legal example exists.

The Italdesign Aztec, designed by Giorgetto Giugiaro and unveiled in 1988, is a rare, low-slung sports car known for its futuristic, "Blade Runner" style. It is unique due to its dual-canopy speedster body, which completely separates the driver and passenger into individual cockpits, requiring electronic communication. The car uses an Audi-sourced turbocharged 2.2-liter five-cylinder engine routed through a five-speed manual gearbox and a four-wheel-drive system. Incorporating features inspired by space technology, the Aztec was produced in extremely limited numbers, with only about 18 examples reportedly built.

The Maserati Boomerang is a one-off concept car designed by Giorgetto Giugiaro for Italdesign, debuting as a running model in 1972. Built on the Maserati Bora chassis, it featured a 310 hp, 4.7-liter V8 engine, capable of nearly 300 km/h. Its extreme, angular wedge shape and futuristic interior—where the steering wheel rotated around the stationary gauge cluster—were revolutionary. Though never produced, its styling proved highly influential, inspiring later designs like the VW Golf Mk1, Lotus Esprit, and the DeLorean.