After launching a coach-built Ferrari inspired by the 288 GTO, British firm 7X Design is back with a one-off, Lamborghini-based build. Called the Rayo, it was unveiled at the Hampton Court Concours d'Elegance in the U.K. last week.

The Rayo is based on a Lamborghini Huracan and features bespoke carbon-fiber bodywork and an upgraded engine. The 5.2-liter V-10 received twin turbochargers from Underground Racing, boosting output from the stock 601 hp to a claimed 1,900 hp.

7X targets a top speed of 300 mph, according to another company, Envisage Group, which made the Rayo's carbon-fiber bodywork and assembled the car. To achieve that goal, the Rayo features meaningful aerodynamic improvements over the donor Huracan, in this case an LP 610-4.

7X Design Rayo

7X Design Rayo

The drag coefficient has been reduced to 0.279 from the stock 0.39, according to Envisage. New body panels were designed by scanning the base vehicle's structure to ensure a proper fit. The Rayo also sports headlight eyelashes, a nod to the Lamborghini Miura.

7X hasn't discussed building customer copies of the Rayo. It previously quoted a $2 million price (plus the cost of a donor car) for duplicates of its previous coach-built supercar, the Ferrari 488 GTB-based GTO Vision.

It's worth noting that the Rayo is based on an older version of the Huracan. Since the LP610-4 launched, Lamborghini has launched more-aggressive versions, most recently with the track-focused STO. Short for Super Trofeo Omologato, the STO was envisioned as a road-going version of the Huracan Super Trofeo Evo race car. In contrast to the Rayo's focus on top speed, the factory-built STO was designed to quick lap times, with aerodynamic changes primarily aimed at increasing downforce.