You've probably seen your fair share of Autobahn top speed runs, but this one takes the proverbial cake. Real estate mogul Radim Passer is the protagonist of a spectacular video shot on an unrestricted section of the German motorway where he managed to hit 402.5 km/h (250 mph) back in 2015 with his Veyron. He took delivery of the W16 machine's successor in 2018, and earlier this year, he returned to the Autobahn to break his personal record.

After shipping the car back to Bugatti in Molsheim in France to undergo an inspection and make sure it would be able to crack the 400-km/h barrier, the 58-year-old businessman headed in July to the Autobahn to drive the hypercar at its full potential. The high-speed run took place early in the morning, at 4:50 AM, so there would be less of a risk the other cars would foil the attempt. It turned out to be a smart move as the Autobahn was almost empty, thus creating the ideal conditions to push the Chiron to its limit.

Gallery: Bugatti Sur Mesure Chiron Pur Sport

He managed to raise the analogue speedometer's needle up to 414 km/h (257.2 mph) without breaking any laws. As you all know, the Chiron is considerably faster than that considering the Super Sport 300+ is limited to 273 mph (440 km/h) and an unrestricted prototype reached 304.77 mph (490.48 km/h) in 2019 at the Volkswagen Group's Ehra-Lessien test track.

Bugatti has officially retired from chasing top speed records, but the company's test driver Andy Wallace did say the car was still accelerating at 304.77 mph. Less drag or a longer road would've been necessary to achieve a higher speed, possibly crossing the symbolic 500 km/h (310.6 mph) threshold.

It's worth mentioning the Chiron without inserting the top speed key is electronically governed to "only” 237 mph (381 km/h), which still makes it one of the fastest road-legal production cars ever.

Hennessey with its Venom F5, SSC North America with the Tuatara, and Koenigsegg with the Jesko Absolut will all try to dethrone the Chiron SS 300+ at one point.