Even faster runs from the Veyron : 407.5 km/h (253.26 mph) in Ehra-Lessien test track, Germany under TUV supervision:
http://en.wikipedia.org/wiki/Bugatti....4#Performance
And 415 km/h (257.92 mph) in Salt Flats, Utah:
http://fr.wikipedia.org/wiki/Bugatti_Veyron#400_km.2Fh
That's even faster than the 1-off Sledgehammer
