The diesel clatter noise is very minimal when you're in the cabin so no worries. Plenty of BMW specialised workshops who knows how to service so no worries. Plus, what Mavik highlighted is true, diesel engines are more bulletproof anyway.

Under BMW BSRI, all SCs will be using Petronas or Castrol 5W-30 Fully Syn. While some 3rd party workshops are using 5W-40. Both are acceptable & are similar to engine oils used for petrol cars. Service intervals under BSRI is now set at 15k km but most of the owners are doing mid service intervals at every 7-8k km outside SC, which doesn't void the warranty. Per oil change with 5.2L of engine oil, oil filter & labor should be around RM350.