Ok, got La Sarthe done on the second try.
First try with the Peugeot 908 only got me 3rd overall. But it taught me about how I could win it.
I used a new untuned Audi R8 with Stage 3 Turbo, oil change, added 40 kg ballast, raised aero to max and raised top speed to "245". Then detuned engine to get in under the limit. Started with a L31 driver and he did the first three laps on RH tires. He worked his way up to 5th in those 3 laps and pitted with the leading pack right in front of him. Switched to intermediates and a L35 driver, and got out of the pits ahead of the 787B, so up to 4th. Then engaged in a battle with the AI R8, Oreca R8 and Bentley in the leading pack. Eventually my R8 and the AI R8 broke free of the other two and started building a gap.
At the end of lap 7, my R8 was right behind the AI R8 and 20 seconds clear of the Bentley. I pitted on lap 7 for a fresh set of intermediates, kept the same driver. Came out in 4th, caught and passed the Oreca R8 quickly before engaging the Bentley. The leading AI R8 had cooled down and lost his drafting partner, so I was setting much faster sector times than him. Things looking good at this point, as I would jump the leader when he stops. But disaster struck. At the Mulsanne corner on lap 9, my R8 and the Bentley went in side-by-side and both overshot the corner and into the sand. My Audi R8 waited to let the Oreca R8 by first and then gingerly re-entered the track, tires were half gone. The AI R8 came out after his lap 9 pit stop ahead of my R8 by a few seconds, so my driver would have to overtake on track to win. My driver passed the leader coming into Indianapolis and then held it off to win by .139.
If someone is having trouble with this race and doesn't have a chapparal (or high level drivers), you could try what I did. Just make sure your drivers don't get too hot near the end of the race.