Among the rarest models BMW has ever built and the first to be created entirely under the purview of its elite M division, the M1 is a hand-built homologation special developed in the late-Seventies as the German automaker sought to compete at higher levels of motor sports.

Intent on using a mid-engine layout, BMW initially contracted Lamborghini to develop the M1 chassis, its tubular steel spaceframe said to have been devised with input from noted Italian engineer Gianpaolo Dallara.

Lamborghini’s ensuing financial struggles delayed development and dissolved the partnership, but a group of disenfranchised engineers from the Italian automaker banded together and founded their own company to complete the work.

The final product was impressive, featuring a rigid spaceframe and sophisticated, double-wishbone suspension with adjustable coil springs and Bilstein gas-filled dampers.

Angular fiberglass bodywork by noted designer Giorgetto Giugiaro gave the M1 visual appeal commensurate wit...