By the way has somebody followed 24 Hours of Le Mans? I found very interesting that they managed to create very free rules under which all the three main contenders were able to lead the race for some time despite having very different power unit (Audi - 4.0 V6 turbo diesel with low-level recuperation into flywheel KERS; Porsche - 2.0 V4 turbo petrol with high-level recuperation into batteries; Toyota - 3.7 V6 atmospheric petrol with high-level recuperation into supercapacitors). In the end the race was decided by mechanical failures.