McLaren Special Operations has unveiled a rather interesting one-off supercar.

Called the McLaren X-1 and based structurally on the company's groundbreaking carbon MonoCell but with a totally unique body, it has been created for an anonymous car enthusiast.

"One of our clients who already owned a McLaren F1, a Mercedes-Benz SLR McLaren and now a 12C, wanted a unique car," says MSO Programme Director, Paul MacKenzie. "The conversation began with our Executive Chairman Ron Dennis almost three years ago - before the 12C was even launched. The client wanted a machine that had all the capability of the 12C but wrapped in a unique body that reflected his needs and personality."

In a subsequent meeting, Mackenzie and Design Director Frank Stephenson went to see him to start to explore the sort of car he wanted.

Says Frank Stephenson: "The key qualities the client desired were 'timeless and classical elegance'. Which was some challenge."

That meeting with Mackenzie and Stephenson lasted for almost three hours. From the pages of notes that were gathered, the design team brought together hundreds of images from the world of automotive, architecture, fashion, design and even film. These were then presented to the customer, and were then narrowed down to a mood book, full of inspiring images from which the design spirit of this unique car would be derived.

Inspirational cars included a 1961 Facel Vega, a 1953 Chrysler D’Elegance Ghia, a 1959 Buick Electra, a 1939 Mercedes-Benz 540K and a 1971 Citroën SM. There were various examples of architecture - including the Guggenheim museums in New York and Bilbao - plus a Jaeger LeCoultre art deco clock, an Airstream trailer, a Thomas Mann Montblanc pen, a grand piano - and an eggplant. "The client liked the shiny texture of the finish," notes Stephenson. There was also a black-and-white photo of Audrey Hepburn.

"The client wanted a competition between external designers - some outside the automotive world - and McLaren's own designers," says Stephenson. In the end, a design by McLaren's Korean-born RCA graduate Hong Yeo was chosen, and completed under the direction of Stephenson.

The unique body of the X-1 means most dimensions have changed. The X-1 is 4658mm long - 109mm longer than a 12C. Width is 2097mm (with mirrors) - an increase of 188mm. Despite the revised roofline, the height remains the same, at 1199mm. Kerb weight is almost identical (about 1400kg), as the lighter carbon body panels compensate for the greater length and width. Light weight, as with all McLaren projects, was a priority.

While the basic architecture of the interior did not change, personalisation includes bespoke Harissa Red McLaren Nappa leather used for the seats, door and roof trim, and switchgear with machined nickel-coated, aluminium bezels. The carbon interior trim has a titanium weave, to give a magical 3D-like effect. Special Andesite tufted carpet covers the floor.

All these changes ensured the X-1 needed special homologation for road use. The car has been thoroughly engineered to be usable and road legal. The X-1 shares the same the major mechanical components as the 12C, including the twin-turbo engine, giving astonishing acceleration and top speed.

Stephenson explains: "The X-1 epitomises how we can not only create a truly unique product tailored to the client, but also enable the client to become a key member of the design team throughout the process. It has been a truly rewarding and unforgettable experience.  And I think that we as a team have created a completely unforgettable car that is true to one man's vision."