Check the Who What Where thread for others, but I am sure that Rusty and his party occupy a significant part of Karting Nord.
If you don't find them beforehand, look out for a large gathering of people on Friday evebing, with impressive fireworks display sometime in the early hours of Saturday.
You're best chance of finding a mass camping of CAers is on Maison Blanche as there are a couple of seriously large encampments being set up which would be hard to miss (don't forget that Drinking for Holland is also represented on CA).
If all that fails, then, as Ian says, the Champagne Bar at 9 pm on Saturday is reliable. It's at the top of the village, by the end of the tunnel.
Hope to see you there - by this time tomorrow I'll be on my way