You realise that BMW eventually relented and suggested the ATF change at 160k km (100k mls).......stated in the service booklet for that generation of cars. At least that's what mine said in 2004.For my 01' BMW, the transmission is sealed "lifetime" fluid ZF automatic. I have changed the fluid when 140k miles on the clock. It shifts smooth before and after fluid change. Now it has 160k miles on it.
I plan to have transmission fluid change on my M3 between 60 and 90k miles.