S550: B0 Service (Oil Change, Cabin Air Filter, Brake Flush)
Right on time, the maintenance minder informed me that it's time for the B0 service, which is (a) the annual oil and filter change; (b) biennial brake fluid flush; and (c) annual cabin air filter replacement. My local Mercedes Benz dealer wants $1067 for this routine service. Inconceivable!
The good news is that I'd already done a brake fluid flush as part of the brake service that I did in September. As for the cabin air filter, the OEM filter (part # 222-830-04-18) is ~$100 (that part is actually two separate filters, as show in the photo). I replaced those myself, aided by a helpful YouTube video. It's an easy, 15 minute job underneath the glovebox, requiring only a torx bit.
That left the oil and filter change, which I had the dealer do for me for $200, mostly because they throw in a complimentary car wash and Uber rides to and from the dealership.
That should do it for another year!