I have a 94 525i and asked Service Advisor in BMW dealership if I need to change tranny fluid. I am told if there is no tranny dipstick under the hood, means that tranny is sealed and has "lifetime fluid" and therefore no need to change for the life of the car. Bought the car used 2 weeks ago and it's my first bimmer. no manual and no history maintennance from the previous owner but my mechanic says it seemed to be well maintained. Very happy with it. Any comments or advise will be much appreciated. Thanks