Bump on an old topic
M5 now comes in 1l cans. (You'll need 4) And also you'll need to (clean or) replace the felt filter of the transmission oil sump. Unfortunately I didn't find the particular P/N PA66-GA33 so opted to clean it with kerosene and later with a carb cleaner.
Be sure to make the gasket with a gasket filler and also apply a bit on the screws and check for leaks when you remove and refix the tranny oil sump! (Demio 2010)