Transmission - automatic

Thank you. Spent untill the wee hours of the morning researching and found the plug, back left. A socket hex was too long to fit but a standard 8mm allen worked. Since I knew exactly what was drained out it was not a real isue of ammount to put back in but I took your advice and went to a BMW shop to verify properly filled. Thanks for your time! I used the (apparently) gold-infused BMW trans fluid listed on the sticker just to ease my mind about compatability - I find it hard to believe some of the multi-use oils do it all effectively. The mechanic recommends flushing at 60k - seems they see a lot of failures on the steptronic at about 100k - and they use a Redline product for refill. Gonna have to noodle that a bit - at least anoother 20k miles!