[elbert]

Yeah, M helmets are accepted at this DE but you really should try to get an SA. Some bmwcca chapters won't accept M helmets.
edit: if you get really desperate, CDOC has a shop on location with quite a few helmets, but you will probably need to go there Friday afternoon as they may not open early enough Saturday morning.

Other things I can think of:
- bring a tarp
- register on Friday night if possible, IIRC D group usually goes first and you do not want to miss your first session.
- did I mention drink lots of water?

I have a white e46m3. Not sure which run group, sometimes A or sometimes B depending on their mood. I usually park with some other e46m3's in the middle of the paddock somewhere. Stop by if you want.