In 2017, Rolls-Royce built a $13 million one-off car for a wealthy client who wanted something unique and exclusive. Called the Sweptail, it was based on the underpinnings of the brandâs flagship Phantom Coupe, but had a unique body with an aeronautical, windswept design, featuring a hardtop roof flowing into a V-shaped rear windshield. Now, the venerable British ultra-luxury automaker has announced another similar, and similarly expensive, commission: the Rolls-Royce Boat Tail. A nautically inspired four-seat convertible built on the stately Architecture of Luxury platform that underpins all of the brandâs current offerings, the Boat Tail takes seriously its connection to its exemplar.