sorry if I'm a bit late for this but I'm definitely down for a meet. I'm stationed at Scott AFB, which is all of 30 minutes from downtown STL. I've been there for over 3 years now so I know the area kind of well, and I'll be coming back from my deployment by the end of May hopefully. I just joined Chitown Subaru on fb last night too and I've seen some posts and promotion about it there. I think the whole thing is a great idea and I'd be happy to help with organizing/planning if it became an annual meet, as long as I'm still stationed here.
I'll also put out the word to some buddies of mine from base, we have a pretty decent sized subaru family on base. I also know some guys at Fort Lost n the Woods(Ft. Leonard Wood) and Whiteman AFB that I think would be down for something like this. But shoot me a PM or we can chat here, and if we can solidfy some dates/times/locations, I'm sure if we wrote in to a magazine or two they wouldn't mind putting out a blurb or something for added promotion.(done something similar for military functions)
Also, clicked the link you had for registration, and it was a no-go. Came up with a blank internet page.