I do about 10k a year, and unfortunately most of it is rubbish city driving through traffic to work and back. I try give it the odd blast on the motorway once in awhile though. I think I have noticed it drinking more recently probably as you say Gaygle because it's been getting closer to service time.
Kwikfit charge £30-£40 for a complete oil and oil filter change, but they use oil that is 10W60 for this car. When I rang my local BMW Specialists he said they use 5W30 Valvoline. I've been using, as I said Castrol 0W30 which made me think, am I still using the best oil for the car. I'm no expert on engine oils...