I have been going to each event since 2008 with a group of Pantera owners, and really looking forward to 2022 with what has been a 4 year hiatus.
When purchasing tickets you'll need General Admission, Paddock & want a Grandstand ticket. Each year seems to be bit different, but the event is now more popular than he 24 Hours so don't rely on getting tickets when you get there. A covered grandstand ticket allows you to get out of the rain (we have had some really wet years camping) and with the ACO Grandstand ticket we used to get ACO Club access for a few years, but I think they clamped down on that.