Still haven't replaced those fluids, but have been noticing slightly more rougher shifts on the transmission. It's possible the levels are slightly lower, but at that point I'd consider just topping it off than draining it. I may have the dealer look into it first, and judge from there. I could even request they check the transmission oil level, and top off as necessary (same with PTU, and RDM). They say it's all a lifetime fluid, but they say nothing of you can't top it off.