Remember, engine oil is a lifetime fluid also if you don't change it...make sure that filter is
changed along with fluid. Problems arise if you only change the fluid, or have someone do a flush with typical ATF and not the proper hydraulic oil that ZF (tranny manf) requires. You cannot hurt the tranny by changing the fluid unless you underfill it or significantly overfill it, or not change the filter or put in the wrong oil. Do it correctly and you can't possibly hurt the tranny. ZF says to change it, AoA (and not Audi Germany) is the only one saying to not change it. Why? Answer is that the lifetime fluid thing is a marketing driven thing, not engineering driven. No required change = less official maint cost. Total BS.
VW pulled the same crap - owner's manual calls for tranny fluid change, VWoA says it is now lifetime fluid - uhhh, it wasn't a lifetime fluid when it left the factory, but now suddenly has morphed into better fluid? I changed mine DIY (posted about it here in Nov of '05) and it has been great ever since. Do it!!!