I guess "I have to have a choice" still rules
. But, most entries on this forum talk about how you should use BMW parts and how expensive they are. This is one area where the BMW parts is less.
(For non-racers, other than anedotal statements, can anyone really prove that any modern, major brand of synthetic oil is better than another? Hopefully BMW has done this analysis to prove that their oil is "at least as good as any other". When is the last time anyone has had an internal engine failure that can be traced to using an "inferior" oil - I would guess never?)
Disclaimer - Just like BMW's "lifetime fills" are generally thought of as 100,000 miles, these statements are directed at the 100,000 mile car, because I think 95+% of owners don't keep their cars over this mileage. For those who do - use your own judgement.