The Koenigsegg One:1.
As you watch the video, you will see that Robert does not simply go to 300kmh and then apply the brakes. That would be a test of the driver’s reaction times rather than a pure test of the vehicle.
Robert accelerates past 300 kmh to 340 kmh and then applies the brakes. This is partly to exceed 200mph, the measurement of which was a secondary goal in this session, and also to ensure that full brake pressure (both mechanical and aerodynamic) is in place by the time the car has decelerated to 300 kmh.