I was looking at doing a DE in CT (Lime Rock Park with my 325ix) to coincide with a weekend trip up there and when reviewing the application I find you have to
join the BMW CCA chapter hosting the event.

Not that it is a lot of $ ($15-$30 I guess) but the first time I have ever seen that.
I am glad I haven't come across this with PCA over that years. BMW CCA NJ claims to require this to maintain their .org (non-profit) status.
Interesting...
Jase