I have just been reading my way through all the post of this thread and I think it's a great idea, something I'd love to be a part of now that I think I have my screaming headset problem sorted. The idea of endurance racing in GT cars with a decent level of damage is great as it forces people to drive for the conditions and their place in the race, which makes it more realistic. The one thing I couldn't find was when such an event might be run....
You're a day late dude
We're thinking of having some enduros of this kind in between seasons in future.