Some of us still here for a little longer Mike...... You should have no problem getting an Enciente Generale at any of the entrances. Not so sure on parking passes though if you will be needing one. If you do, the online ticketing site could be a source, and, if available you should be able to print your own, same goes for the general entries. Tickets still available online at
www.lemans.org.
As others have mentioned the Navettes/Buses out to Mulsanne/Arnage are a bit of a nightmare these days, not just queuing to get on but the hellish nature of the traffic during race time. Better than driving yourself though :-)
Pete