The BMW M5 is a high performance version of the 5 Series executive car built by the Motorsport division of BMW. Beginning production in 1986, the first incarnation of the M5 was hand-built utilizing the 535i chassis and a modified BMW M1 engine, being the fastest production sedan in the world at the time of its introduction.^[1] Subsequent iterations of the M5 have been built from each generation of the 5-Series platform, including the E34, E39, E60/E61, and most recently, F10, with the first orders delivered in late 2011.