Here an account of FC508 done in 2001. It's a special breed that does this race.

http://www.midcalracing.com/5082001/5082001.htm

I especially like this part:

"About 3 a.m., around 300 miles into the race, while on the climb up Salsberry, looking well up the hill, I could have sworn there were vans lined up on the side of the road with bikes on top. I felt great, thinking I was passing all these riders who had stopped to sleep or recover on the hill. It really did motivate me. However, as I went on, I realized that the car lights behind me were reflecting off the little 4 foot high poles with reflectors on them on the side of the road, which in my mind looked like vans with bikes on top. It's amazing how many I had to pass before I figured this out. Lesson: The mind often sees what it wants to. "