I'm not being disrespectful, but isn't that a cop out? all kinds of test "pilots" know the risks of going fast. Going over 80mph and sustaining that speed, is a pretty big risk. To do 277,with the same hazards, was a risk to the pilot. Why stop now?
Where else can 300mph be reached, in a controlled environment, to make it an official run?
Even in a controlled enviroment, you're still talking about a one-and-a-half ton car flying at 300 miles an hour. The amount of kinetic energy in that is just enormous.
277 MPH: 10,717,072 Joules
300 MPH: 12,515,332 Joules
Plus, the mechanical strains on the car would be significantly worse than the Veyron at 253 - if you remember, the Veyron's tires would last all of 15 minutes before blowing apart. That's at 50 MPH below the hypothetical 300+ speeds. At 300, I don't think the tires would last long enough to maintain 300.
Plus, if the road surface is uneven, the car feels it in a far more extreme fashion at 300 than at 277 or 253.