Here some production numbers of the E53 and especially the 4.8is (these also include cars produced for BMW internal uses, testing aso.):

BMW X5 E53 produced for the whole world: 616.841

BMW X5 E53 4.8is worldwide: 11.724
BMW X5 E53 4.8is, LHD, worldwide: 9.990
I've missed to write down european LHD models, but it was about 1170
BMW X5 E53 4.8is, LHD, Germany 704