I remember talking to j0n about it, he's been on it before (in the vette I think). My boss has been down it on his harley as well. From what I have heard it's usually fairly well patrolled and there is also often a fair amount of traffic, so the odds of you getting in any real "spirited" driving a likely slim.
There are TONS of videos on youtube of people in cars and on bikes driving all or part of it.
http://www.youtube.com/watch?v=6rueC1r8W1s
- Justin