If you're new to MB's, MBCA can be a good way to learn about the cars. If you know you're way around them already, the politics can be depressing. Don't join for the 10% discount, you can beat that by buying ANYWHERE on the web, here, Rusty in Atlanta, Randy Steele at EPS, etc... The only times I go to a dealer for parts are for the body specific parts that no body will carry except the dealer. For example, I just put a water pump, serp belt tensioner and shock in my 1991 300TE. The list on the tensioner was $235. I found it on sale at Rusty's for $95!! I'm not talking alternate brands, I'm talking OEM. Same thing for the water pump, a Graf new pump for $110. The 10% discount at the dealers isn't close to what you can get by looking around.
Disregard this if you bought a new Benz, have lots of money, and like the peace of mind of having the dealer perform all of the maintenance. You didn't buy an inexpensive car if you're in this group. I put $720 in parts into my TE, and I figure it would have been over $3K for parts and labor at the dealer. That's alot of difference in my book.
Back to the MBCA, it's either the best gig the Star publisher ever dreamed of or it's an egalitarian group of upper class car enthusiasts who appreciate rules of order and the tri-star marque. It all depends on who in the club you ask and how the last board meeting went. It was very entertaining while I was a member for 4 years, but I ultimately decided I was not getting $45 of value per year out of my investment. YMMV.
has a leadership list where they love to vent and ramble about the club's politics. Very entertaining if you have the time.