Engineers at 9ff finally accomplished their goal of beating the Bugatti Veyron’s 407km/h (252mph) top speed back in April using their highly modified GT9 supercar, which posted a new top speed of 409km/h (254mph), and now the car is ready for sale. The world record for the fastest production car, however, is still held by America’s SSC Ultimate Aero TT, which reached a top speed of 411km/h (255mph) last September.

The GT9 may be a production model but available examples are hard to come by as the car will be built in an extremely exclusive run of just 20 examples and each priced at €498,000 ($785,677). Although the GT9 is loosely based on a Porsche 911, its mechanical package has been totally revised. Ditching the 911’s rear-engine layout, 9ff engineers created a custom mid-mounted engine design utilizing the tuner’s twin-turbo 4.0L flat-six engine. Peak output stands at 987hp (726kW) and 710lb-ft (964Nm) of torque.

The 911 GT3 body, on which it’s based, has also been stretched by 300mm and has had the roof lowered by 120mm to maximize downforce at high speeds. Thanks to carbon-fiber and Kevlar construction, the entire vehicle weighs in at just 1,326kg. Surprisingly, the car's Continental Vmax are only rated up to 410km/h, 1km/h shy of the Ultimate Aero's top speed.