I had autocross in all wet the other day and everything seems to have survived. I did tape up a few of the more sensitive areas to try and prevent water. My friends want me to stud up some tires and do an scca ice race... But im not convinced i can get it that water tight ha!
I think you just have to be conscious of what used to live inside your doner, since many of those electronics are not made to take water. A few folks have said power steering gets angry when wet, so thats one known sensitivity. Engine side, everything is a weather ready connection, so nothing to worry about back there.