Proper supercar ? Quite likely, BMW thinks back about the E26 M1 with mixed emotions. Back in the day, due to adverse circumstances, the commercial version of the E26 M1 had a complicated birth:
"The project’s failure had become complete by 1980. The budget of BMW Motorsports had been slashed nearly 75 percent. The Procar contract was sold to England’s BS Fabrications. Under attack internally for diverting engineering effort from street cars, and yet anxious to develop the turbo four-cylinder for Formula 1, Neerpasch left BMW Motorsports. Everyone understood that the M1 had failed as a race car because its development proved too costly and could not keep pace with changes in racing regulations—two important failures in silhouette racing, as any IMSA or NASCAR competitor will attest.
The production of the M1 halted in December 1980 at 430 cars—35 to 40 of which were race cars. Since family sedans had saved BMW from bankruptcy in the early Sixties—not exotics like the 507 sports car—BMW saw little reason to perpetuate the M1 in the face of what it saw as a declining market for exotics."
(source: here)