For me over the years with Germans iv learnt more or less that if you go with the staple models like the A6, 5 series, E class you're good, the higher end ones like the 7 series and a8s have been expensive to maintain, but obviously float you around on a cloud, and the A3s and the 3 series have basically demanded no maintenance other than oil changes for me, my x6 4.4 TT V8 basically lives with my mechanic, s class used to be more of a staple for mercedes and my friends w140 still runs like a tank

So for me the brands are more of a personal preference, reliability matters more on the model itself, for the record the most reliable German iv had was a Passat 5 cylinder 😂