Exploiting the air in any aerodynamic way comes at a price, of course, because physics won't really give anything away for nothing – just as your mobile phone service provider won't. The price is aerodynamic drag. We know it increases as the square of the car's speed and that the power needed to overcome it will therefore increase broadly as the cube of it. So a 300mph Veyron would require even more than its current 1,200bhp. I've worked it out roughly as 1,870bhp, not allowing for the increased drag of an inevitably bigger cooling system. Let's call it 2,000bhp.