BMW celebrates 50 years of M division with hardcore M3

May 24, 1972, was the day the agreement was signed to establish BMW M, meaning the BMW in-house tuner and motorsports division turned 50 today. BMW is celebrating the occasion in a big way, having already revealed a modern CSL based on the M4 coupe and preparing to reveal both a standalone M car in the form of the XM SUV, plus the first M3 Touring…