Rolls-Royce has revealed what is thought to be the world’s most expensive new car – a coachbuilt grand tourer estimated to be worth around £20 million.

The Rolls-Royce Boat Tail has been launched to spearhead the luxury brand’s plan to expand its coachbuilding into a permanent part of its offering.

Custom-built to meet individual buyers’ demands as part of a four-year collaboration, three examples of the bespoke two-door, four-seat grand tourer have been built, all based on the Phantom platform.

The first car to be finished was inspired by the commissioning customers’ own 1932 Rolls-Royce Boat Tail and features a climate controlled “hosting suite” hidden beneath a unique rear deck which opens with a butterfly-style movement. Beneath the motorised panels are two fridges housing the clients’ favourite champagne, along with a bespoke cutlery and crockery set, cocktail tables and two purpose-made carbon fibre stools. The self-contained picnic area is finished off with a telescopic parasol which extends from between the leaves of the boot lid.

To match another of the customers’ passions, Rolls-Royce spent three years collaborating with luxury watchmakers Bovet 1822 to develop a pair of matching timepieces that can be worn by the owners or placed into the car’s fascia to act as a clock.

Although the Boat Tail is based on the Phantom’s platform and shares that car’s 6.75-litre V12, almost every element is new, with 1,813 completely new parts developed for the car, including every body panel. Even the 15-speaker sound system was redesigned to make sure it was optimised for the open-top body.

The colour of the car’s paint is also unique, developed to match the owner’s favourite shade of blue and reflect the car’s nautical links. In a first for Rolls-Royce the bonnet features graduated shading, which is reflected in the different coloured upholstery between front and rear seats.

Rolls-Royce says the Boat Tail cars were inspired by the luxury J-Class yachts of the past as well as previous boat tail cars, which were created in the 1920s and 30s when coachbuilders combined Rolls-Royce chassis with the “hull forms” of sailing boats.

Demand for the cars was sparked after Rolls-Royce unveiled the one-off Sweptail in 2017. After that car was revealed several well-heeled customers asked to have their own unique models, prompting Rolls-Royce to launch its new coachbuilding service.

Alex Innes, Head of Rolls-Royce coachbuild design, commented: “Coachbuild provides freedom to move beyond the usual constraints. Normally, there is a natural ceiling to Rolls-Royce Bespoke by way of the canvas. At Rolls-Royce Coachbuild we break through that ceiling, embracing the freedom of expression afforded by coachbuilding to shape a concept directly with our commissioning patrons.

“Boat Tail is a distinct counterpoint to industrialised luxury.”

Torsten Müller-Ötvös, chief executive of Rolls-Royce, added: “Historically, coachbuilding had been an integral part of the Rolls-Royce story. In the contemporary Rolls-Royce narrative, it has informed our guiding philosophy of Bespoke. But it is so much more. Rolls-Royce Coachbuild is a return to the very roots of our brand. It represents an opportunity for the select few to participate in the creation of utterly unique and truly personal commissions of future historical significance.”