BMW Motorsport Headquarters

BMW M GmbH (previously: BMW Motorsport GmbH) is a subsidiary of German car manufacturer BMW AG.

BMW M, also known as M-Technik or just "M" (for Motorsport) was initially created to facilitate BMW’s racing program, which was very successful in the 1960s and 1970s. As time progressed, BMW M began to supplement BMW's vehicles portfolio with specially modified higher trim models, for which they are now most known for to the general public. These M-badged cars traditionally include modified engines, transmissions, suspensions, interior trims, aerodynamics, and exterior modifications to set them apart from their counterparts. All M models are tested and tuned at BMW's private facility at the Nürburgring racing circuit in Germany.

http://en.wikipedia.org/wiki/BMW_M