Had to cancel on the Willis because I was in England for two weeks.
I will admit that England was nice.
Passing is allowed anywhere on the course.
A wave-by is not required, but bumping (while it can be fun at times) is frowned upon.
The course has very little run-off room, no flagmen, and no tire barriers. The spectators stand far too close for comfort (similar to Rally racing) and there are simply too many hills.
Believe me, you'll only want ONE session.
But hey, at least you get a T-shirt out of it.