I never follow BMW's bullshit service intervals. I service mine at 3000-4000km with MANN oil filter. 5-40 Castrol Titanium.

I'm servicing the BMW more regularly due to the fact the previous owner of the car, and the nature of the original Service intervals. I can tell the motor is getting better and better everytime I drop the oil. Its breaking down all of the gunk build up from the service every "10,000-15,000km" intervals. 244,000kms At the moment.. and motor getting stronger than ever. Need to replace VANOS though.