I am in Oklahoma as well, and I would never join anything on facebook. I would assume that any serious "club" has their own, dedicated website and dedicated forum for members to join the local discussions (and not advertising some third-party website that's known worldwide for their privacy violations as their monetization scheme... ugh).
That said, where in Oklahoma - preferably close to Norman - do Tesla drivers go to get their windows tinted, considering how difficult the M3's rear window is to do in one piece?