Car which is currently fastest car in the world?

Koenigsegg One:1 is currently acknowledged as having the highest top speed of any production vehicle on the planet, it replaced the Bugatti Veyron in that position. IT reached a speed of 273 mph.

However it is difficult to test a cars maximum speed when it exceeds 250 mph due to the limited number of places in the world where a car is able to safely reach such a speed. Because of this, it is believed some cars (including the Ultimate Aero) may have the capacity for as much as 270+ mph.

An incomplete list of possible contenders includes the Saleen S7 Twin Turbo Competition, the Vector WX-8 A-VTech HPV, and the Koenigsegg CCX and CCX Edition (only 14 Editions were ever made, perhaps negating its status as a production vehicle).