Do air races count? Build a plane in a garage. Fly to Cleveland. Go 250 mph and die.
Don't laugh but I have been racing since the 80's and I shudder thinking about the things we use to get in and drive.
However that said go back to the 50's and 60's and those guys had huge ones to do what they did.
Not technically a road course, but I think the nuttiest CARS raced today have to be here.
EDIT: Isle of Man is unquestionably more dangerous, but the cars aren't as insane.
You'll need to log in to post.