The biggest obstacles on that particular course, aside from the obvious cones, were the ruts. It is on some old farm land, and is very loose tilled up soil. The 4wd and over 2.4L class went first, and creating some big ruts for the littler 2wd cars. When I was trying to take a certain line around a turn, my tires got stuck in the ruts almost every time, and when I was trying to slide the rear end, it usually got stuck in a rut and stopped sliding.
The only good thing about ruts is that once your tires are stuck in them, they help you get around the turn, usually the outside front wheel takes most of the force and helps steer you.
Last year at the same site, an Impreza with a H-6 motor took a turn real fast and slid into a rut sideways. The inside wheels came off the ground about a foot or so. It looked really cool, but I'm sure it's not good for the car to do that all the time. I think one or both of it's outside tires broke the beads.
It happened to one of my last year tires too, that's why I always run 42-43psi, esp in the front. That's also why I got a beater car... I just don't know if I can fix it up in time for the next event.
^^I've always wanted to try ice racing too. In 2yrs I plan on moving to Michigan, I think they do ice racing there.