Check out M-Gruppe. We're a club of M-exclusive car owners with local chapters across the country (and even overseas), supporting our members with local events like C&C or Drive-&-Dine, a motorsports council to help arrange track days, participating dealerships and vendors who offer discounts, and so on. Heck, we even had tours of the BMW processing centers at the ports.
It's a great group of folks. FREE TO JOIN, but you MUST have an M-car to join and provide your VIN number to prove it. Your car must have a WBS prefix, and must have rolled off the line as an M-car. It can't be a regular production car that's been modified.
https://www.mgruppe.org/
We also have a private Facebook group, accessible by invitation. Start with the website, and then you'll get access.