No matter what anyone else tells you, the only approved oil for that car (IIRC) is Castrol TWS. It costs a fucking fortune.

I have the same issue with my M5.

Best I can offer you is to find the castrol classic oil page, and buy direct. BMW will try to sell you a litre for about 14-15quid!!!!! You can get direct a little cheaper (works out to be 10quid a litre)

Cheers mate

JJ