BMW Z21 ‘Just 4/2’
Something of a historical and engineering curiosity, the BMW Z21 ‘Just 4/2’ was a 1995 study by BMW Technik GmbH for a minimalist two-seater sports car with similar appeal to a Caterham or, more recently, KTM’s X-Bow.
As on those trackfocused specials, the Z21’s wheels and suspension were separated from the main fuselage, and an exposed lightweight frame carried the front- and rear-suspension mounting points as well as the rollover hoop and the mounts for the 100-hp, four-cylinder engine, taken from the K1100 motorcycle.
Though there was no windscreen or roof, BMW’s wind-tunnel-honed aerodynamics promised reasonable protection from the worst of the weather. Regrettably, however, these qualities would never be put to the test as the Z21, also known as the Just 4/2, was never considered for production.