Also be 5miles over on a 15k oil change and 'Sorry Sir, not changed in accordance etc etc etc'. I change mine at half the recomended intervals and expect long engine life and zero problems. Castrol BMWLL01, GTX and Magnatec - depending on which of my cars it is.
Good - Fast - Cheap: Pick any two.
E23 735i; E32 735iL (X 2 - 1 Alpine White and 1 Glacier Blue); E34 535i; E38 735iL; R50 Cooper; R55 Cooper Clubman.
E21 318i; E30 318i; E32 735iL; E34 535i; E38 730iL; E53 4.4i