for the record,,, what he said is known to be true in some bmw trannys.
5hp30 in my 540 for example.
there are a lot of write ups on this, If the tranny has never been serviced,
they suggest changing the filter and whatever fluid comes out ONLY after
100k ( if anything), or you will very possibly have major problems.
Lifetime is 100k, the first owner, and warranty are gone by then, the car is
disposable to bmw after that.