^ Agree with the above, I retract my previous blanket statement about having to bleed ATE fluid quarterly or after every 2-3 track days. I'd do that if your car sees the track, but if it's just a DD you can probably get away with flushing it every 1-2 years; personally I wouldn't wait 3 years under any circumstances even though BMWs from 3/11 production onward now have their computers programmed for 3 years rather than 2. In fact now that I think about it, my favorite indy mechanic out here uses ATE on all the cars he sees as well unless it's incompatible with the car or the stock fluid is better -- so OP, if you have ATE, don't sweat it. But if your car won't be on the track, there's certainly no need to go out of your way to get it. Good luck!