I don't think people who buy a Veyron would worry about that, it's not just a case of having a couple of million tucked away, these things cost an absolute fortune in fuel and servicing too. I read a story a few years back where a rich Arab in London paid £17,000 to service his Lambo, he actually flew it privately back to Italy, imagine the carbon footprint!
I have pondered this...I think I would try a time or two just to see, but I wouldn't regularly do it. Then again, even as a kid I wasn't into supercars. Though probably not for the reasons some here might cite for not being supercar fans.
I hypermiled once or twice with all the cars that I have owned, just because Iím curious and saving gas is good. I hypermiled my 5.5L V-8 Mercedes once and got 25mpg; I also had the indicator show 26mpg which was probably correct based on filling up. I also kept to the 68mph speed limit; didnít go slower or faster. When I had the Prius C I did the exact opposite once, I wanted to see what the fuel consumption is going as fast as I possibly could doing the same trip. I was doing 75-87mph the whole trip and once I topped out at 100mph going downhill (this was limited by air resistance and the 99hp combined power). I got 42 (s)miles per gallon. I think hypermiling a Veyron would not change the fuel consumption much; the 16 cylinders are constantly getting fuel and the engine is grossly under stressed at any speed around the speed limit.
Also, I would never buy a Veyron, although Iím glad it exists. They are already working on the Bugatti Chiron, the successor to the Veyron:
Top Gear did a similar experiment with a Prius V's a BMW with I think either a 4.0 or 5.0 litre engine. It was wasn't very scientific but when they thrashed the Prius and drove the BMW at the same rate behind it, the Prius got about 19 mpg and the BMW got something like 22 mpg ha! I thrashed my Clio last year as an experiment, and got it down to 50 MPG, wouldn't budge below, but I didn't have and really long stretches of road so I maxed out at about 70-80 Mph.