The 12C debuted online as the MP4-12C in September 2009, and McLaren began series manufacturing the car in February 2011, at the company's facility in Woking, Surrey.

The "12" in the name refers to McLaren's internal "Vehicle Performance" index, which evaluates cars based on four key criteria: power, weight, emissions, and aerodynamics.

[8] To develop the upcoming sports car, McLaren used modified versions of existing vehicles from other manufacturers as test mules.

The first prototype, called the MV1, was a Ferrari 360 that featured a 3.8-litre twin-turbocharged V8 engine and side vents for additional cooling, which were incorporated into the production model.

McLaren subsequently developed two in-house prototypes, the CP1 and CP2, which featured a "MonoCell" monocoque and were used to test heat management and performance.

[6] In 2008, Frank Stephenson was appointed as the lead design director of McLaren,[10][11] becoming chief of the project late in its development.

[12] The final design of the MP4-12C was unveiled online in September 2009,[13][14][15] with its physical debut occurring at the Goodwood Festival of Speed in July 2010.

[16][17][18] Following McLaren's investment of £50 million into its production facility at Woking, Surrey, which could build approximately 4,000 cars annually,[9][19] the official manufacture of the MP4-12C began on 2 February 2011.

Manufactured by Carbo Tech in Salzburg, Austria,[26] the carbon fibre structure weighs 80 kilograms (176 lb).

[60] The centre console of the 12C is equipped with a seven-inch touchscreen that controls the Meridian entertainment system and phone functionalities.

In January 2016, a 12C HS painted in F1 Vodafone Racing Team colours reportedly commissioned by Ron Dennis was offered for sale at Mecum's Kissimmee auction with 203 miles.

[72] The same F1 Vodafone Racing Team was offered again in January 2017 at Mecum's Kissimmee auction with an estimate of $950,000 – $1,200,000 where it still didn't sell.

To style the X-1, McLaren used ideas from a 1961 Facel Vega, a 1953 Chrysler D'Elegance Ghia, a 1959 Buick Electra, a 1939 Mercedes-Benz 540K and a 1971 Citroën SM.

[74][75] In December 2010, McLaren announced that they would produce a small number of MP4-12C cars in order for them to compete in the FIA Group GT3.

[77] It received its début with a single car entry for the Spa Francorchamps round of the British GT championship.

[80] McLaren released several promotional videos for the MP4-12C in the lead up to the racing season, including one of Formula 1 star Lewis Hamilton driving the car at locations in the U.S.

Tag Heuer produced a limited (1,000 units) series of Carrera MP4-12C Chronograph wrist watch inspired by the MP4-12C sports car.