I've been taking my 2020 Z4 to the Rockville BMW dealership for almost six years and, honestly, I have no complaints other than I've had to sit for several hours in the waiting room when I was simply there for an oil/filter change. I decided to search for a service company closer to my home and found Airpark Auto Pros, only 3 miles from my house. Although they don't specialize only in BMWs, I was very impressed with the gentleman at the front counter and the service provided by the mechanic -- all in about an hour! In addition to the oil/filter change, the battery was checked (and was fine), as well as other fluids. One of the coolest things about going to AAP was that I learned more about my car, its capabilities, etc. when it turned out that he also owned a (2009) Z4. Very nice people. As for the price, AAP is a bit more expensive, which surprised me. I haven't gone to my records to compare, but I believe I paid about $150 at the dealership. Also, at the dealership, they offer 3 oil changes for $249, which makes it considerably cheaper. However, aside from the price, I'm very happy with Airpark Auto Pros and plan to take my car back there for the next oil change!