The Bugatti Veyron is an amazing feat of engineering and the fastest production car in the world with a top speed of 407 kph or 253mph.
The Bugatti Veyron is powered by a W16 engine (2 V8s) which produces 1001hp. To keep it cool, there are 10 radiators and the engine has no cover. The Bugatti Veyron will get you from 0-100kph in around 2.5 seconds but still be a very driveable car.
Bugatti is owned by VW and the car was first designed and then made to reach these speeds without modification of its shape. Top speed is achieved when a special key is entered near the floor and drivers door. This lowers the car and the spoiler is retracted to give less wind resistance.
Want to see what your own Bugatti Veyron, configure it at the Bugatti configurator.