On the french magazine "Sport Auto", i red an interresting article.
The police closed a motorway and clocked some fast cars with speed cameras. They measure a Porsche 996 Gt2 at 318 km/h but couldn't measure the speed of the Enzo, they used two differents speed cameras but no results and the policeman said they could not use a laser gun for this type of speed. It seems the pointed and low nose and shape + important speed are "guilty".
By checking the on board computer they achieved to get the max : 353 km/h. 8)
morals : If you want to make speed, take an Enzo and don't stop at 200 km/h you would be taken, push to 350 km/h ...
(Sorry, I haven't a scanner so I can't put it, but as it's in french, only a few would have understand)