A three-in-one Concept We Forgot, the Nazca M12 revealed at the 1991 Geneva Motor Show was followed a year later by the C2 Coupe and in 1993 by the C2 Spider. BMW and Italdesign got together and used as foundation the Bugatti ID 90 with a 300-horsepower 5.0-liter V12 engine sourced from the 850i. The C2 was tweaked by Alpina to 350 hp while the C2 Spider had the larger 5.6-liter engine sourced from 850 CSi with 380 hp on tap.

You can read all about the three concepts here.