Here’s the key that helped Bugatti do 407km/h

It’s almost 15 years to the day (we’re eight days late, sorry) that the Bugatti Veyron did 407km/h, or 253mph, at Ehra-Lessien in Germany, making it the fastest production car in the world.

Of course it can only do a paltry 236mph usually. Anyone with enough space to reach (and stop from) 253mph has to insert a special ‘Speed Key’ in a slot beside the driver’s seat to unlock the Veyron’s full potential.

And even then the car might not let you – turn the Speed Key and the Veyron’s computers run through a load of checks, only granting access to ‘Top Speed’ mode if specific conditions are met. Tyre pressures even slightly out? No speed for you.

In Top Speed mode ride-height is reduced from 125mm to just 65mm at the front and 70mm at the back, the rear-wing is lowered and angled at two degrees and the diffuser flaps are closed to minimise drag among others.

On April 19 2005, only a few months before production was set to begin, test driver Uwe Novacki hit 411km/h in the Veyron at Ehra-Lessien. A display at the track suggested he’d managed 427km/h – 265mph – but it was later proved inaccurate. So after a load more runs in both directions, the speed Germany’s TÜV Süd entered into the record books was 407km/h. History was made, Mr Piech was happy, job done. For a while, anyway…