I went for about an hour and left. I spent more time in traffic getting in and back out than I did sitting on my tailgate eating kippers and watching the bedlam in the parking and camping area. I kinda wished I'd spent more time down at the Salton Sea instead- the weather was perfect.
It seems like an event that needs to be taught to you. Once I got in, I just followed the traffic until I got to the parking area, then it became a bit more freeform and I didn't see any signs saying "Spectating This Way."