The Peugeot 908 HDI FAP is a great choice as well as any high powered LMP car (anything from the Audi R10, AMG Mercedes CLK-LM Road Car, Nissan R390 GT1 Race Car to the Nissan R92CP Race Car).
I did it in both the 787B & R10, They where both very fun, but the 787B slaughtered the competition.
I kinda want to go back and do it in the 908 or CLK-LM (Backflip?), but it's tough stuff..
You say the 905? That would be a pretty neat car, tough to find though.
It depends on how good you are at Le Mans. If you are a good but not great driver (like myself), you may not want to drive anything slower than the 908. R10, CLK-LM and R390 GT1 are much slower than the fastest AI cars (as evident in B-spec). You will have to turn in very good laps, all day and night, to pull off the win.
I would say a Pesky Courage C60 Race Car '03. Slowest of the LeMans cars but fully tuned can provide a load of fun while keeping the A.I. close behind or ahead of you. I haven't got the time to do no 24Hr event though.
I think the Audi R10 should suffice for you, if you're looking for a challenge, just go at it without a turbo, that thing's pretty hard to get into the low 22X MPH range, well, that's just my observations, but it should provide the challenge.
R10, you'll always stay with the Ai. If you want to be pressured and sprinting the fastest you can the entire race, get a RM Chevrolet ZR1 vette. At 862hp you should barely win. You probably won't even lap the second place car in the whole 24 hours you're given.
I'm waiting for the update which will allow saving of in races games (WHY THIS DOESN'T EXIST ANYWAY IS BEYOND ME)
But the choices you've mentioned seem sweet. I'm actually going to get a load of redbull in and sweets and try and do a 12 hour shift (like 10pm til 10am)
I want something will good fuel consumption, so the 908 it is !
I have just finished my first 24 hour lemans and used the Sauber Mercedes. I was a little bit more than 39 laps ahead of number to, the C60 Hybride at the finish.
