The hardest thing about an autocross is that it is just a SEA of cones when you're out there. It's not like driving on a road, it's hard to remember where the course is. Walk the course (pretend you're a car), look at the map and work it out in your head. I usually tape the map on the passenger seat so that I have a quick reference when I need it.
In the rain? I would just pass on that, but I'm a sissy
when it comes to slick roads.