My 2009 x3 has 109k on the same GM 6L45E tranny you have in your e90. I just changed the fluid the 3rd time at 100k. It shifts as smooth as butter...and that's saying a lot because early post lci x3s got a batch of bad shifting tranny's. Mine was not among that batch (my build date was after the revised control module).
I am not at all worried....I know its a different model but head over to the e46 forum sticky...there is an awesome transmission poll thread there...your fears will soon be dissuaded...
Last edited by x3brian; 01-19-2013 at 09:08 AM.