24 Hours of Le Mans
The "car guys" in our club do a group build on Le Mans race day. We start when the race begins (9:00AM Eastern US time this year) and finish 24 hours later. The only other "rule" is that the car must have run at Le Mans at some time.
My build this year was the 1966 winner, the Ford GT-40. Kit by Fujimi.
More here:
http://www.percongrp.com/pelikan/autos/lemans07_ms.htm