Tuning company that built the 9ff 9f-V400, currently the fastest street-legal car in the world. Achieved a speed of 241.1 mph around the Nardo speed bowl, or exactly 1 mph faster than McLaren achieved at the straights of Ehra-Leissen. However the Dauer 962LM and the Corvette Calloway Sledgehammer have both techinically achieved higher top speeds, the V400 currently holds the official title. Hopefully this debate will quickly be resolved by either the Koenigsegg CCR (expected to hit over 250 on a straight, has already hit 241.0 at Nardo) or the Bugatti Veyron, as yet untested for top speed, although projected is around 252 mph.
The 9ff 9f-V400 is based on a Porsche 911 and is simply put, the best tuned car in the world.