Oh I just remembered a story told by Claude Roulle when I went to the MoTEC seminar, he used to run a Toyota Supra in European Touring car in the 80s. He says in those days every one cheats and they all know about it. For the Spa 24 hours they entered a car that's underweight but when they went for prerace scruitineering they put these special wheels on the car that's like 40 kg each. They just roll the car onto the scale and push it back to the pit. The car retired in the race but he said he wouldn't know what to do if they actually finished. Apparently one wheel at one point rolled away from their pit stall down the pitlane(approach to Eau Rouge is downhill, and thats where the sportscar/touring car pitlane was), the wheel went through 2 concrete wall at the bottom of the hill...