The M6 was critically acclaimed throughout its lifespan for its elegant, aggressive "shark-nose" styling, its luxury equipment, and its performance.
An M6 can be distinguished from other E24 models by a larger front air dam, a rear spoiler, BBS wheels, color matching side view mirrors, M badges on the grille and back, and slightly larger front brakes.
In North America, the E24 M6 was fitted with the catalyzed S38B35 motor, producing 256 hp (191 kW) and 243 ft·lbf (329 N·m) of torque. The non-catalyzed version, only available in Europe, produced 286 bhp (213 kW) and 251 lb·ft (340 N·m) of torque.
The M6 achieved 0-60 mph (97 km/h) time of 6.0 and 6.8 seconds for the European and American versions, respectively.
Source: Wikipedia, 2011