Hello Colin C,
And welcome to CA from a fellow CA'er - also in Oxford (Woodstock!).
I have been going to Le Mans for a number of years (19th now).
On of our group has a disabled lad who attends occasionally - even camping ! - Although he has parental assistance.
Are you bringing the Classic (What is it?).
Obviously if it is RARE, you need somewhere safe to park it.
http://ticket.lemans.org/info-pratiques-auto?Firstly, contact the ACO.
They have ticket deals, free parking and grandstands available for badge holders and their carers. (See attachments)
Grandstands 13, 17 and 23 all have disable access for FREE.
Head to the Grandstands early on Saturday as it will be 20 or 30 people deep in punters 2-3 hours before the start! (allow at least 2 hours to get through the crowd).
Secondly, I suggest you call Setram.
Although I don't have personally experience for disabilities on the Tram, I understand that some stops (maybe not ALL) but certainly Antares does, have disabled access.
Access from Antares to the circuit and village is good from Antares, although access to the outside of the circuit can only be found using the ramps / underpass between "S" de la Foret and Tertre Rouge Corners AND at the underpass at the main (Nord) Entrance (by the Musee).
Finally, I would say that traffic is NOT ALL THAT BAD during the week.
Except on Saturday 4 - 5 hours before race start and 2 - 3 hours after on Sunday and maybe an hour or so before each qualifying session - so Thursday.
Just make sure you leave early AM on Saturday to get to the circuit.
If I can help in any other way, just ask
Dean