You can always get tickets and camping passes for either the classic or the "main" 24 hours race on the various websites , clubarnages.com or pistonheads etc eBay and the like, as people always buy and someone nearly always drops out.
I didn't plan to go to the vingt quatres heures in 2009 then a week before the race changed my mind and got a ferry via Brittany ferries, tickets from e bay and camping pass from club arnages. Easy.
