I would HIGHLY recommend changing the fluid every 30K. Do NOT have the car hooked up to PowerFlush machine when you have the fluid changed...that can cause harm/damage to the internals, possibly causing a clog. Clean, red, unburned smelling fluid is better for the operation of the transmission.
I would also suggest installing a transmission cooler to prolong the life of AX4N. Check out the TaurusClub @ www.taurusclub.com for some more information if you're into doing some of the maintinence yourself. Here's some instructions on flushing it at home if you care: http://www.taurusclub.com/forum/index.php?...nsmission+flush