This is one of 8 original road cars worldwide.

The M12s were intended as McLaren's first customer cars based on the M8As which the team had successfully used to win the 1968 Can-Am season, as well as the M8Bs which the team were developing for 1969. However, the M12s did not share everything from the M8 series. Instead, the monocoque chassis were actually based on the early M6 series initially developed in 1967. On top of this chassis, the aerodynamic bodywork of the M8A was added. The engine bays were specifically designed to house a Chevrolet V8 engine, but several customers opted for other manufacturers. All M12s were built by Trojan, rather than at McLaren's racing headquarters

Several M12s were later modified by customers in order to cope with necessary demands. Many Can-Am M12 customers added larger rear wings for better downforce, in an attempt to keep up with competitors which had already done the same. Two M12s were imported to Japan by Toyota and received revised bodywork to allow better results at Japanese circuits as well as to fit company's own V8 engine. M12 owner Phil Scragg modified his car with smaller M6 bodywork for use in hillclimb events. One final M12 was used by Trojan to develop a street legal coupé for Canadian André Fournier.