Did this today on my 118k 128i with Redline 75W-90 for the diff (
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1) and Redline MTL 75W-80 for the trans (
https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1). Shifts feel much smoother, car is new to me and I doubt it had been flushed before. 10/10 recommend.