Some Background Info:
2003 Pathfinder SE 4x4, bought it used in September, it now has 37K miles, and I don't know if it has been serviced or not. I am also planning on adding a transmission cooler (It gets hot here in Texas).
Also, the maint. section of the service manual only says to inspect the AT fluid every 15K, nowhere in the maint. section or the auto trans section does it say anything about flushing the transmission. The only mention about flushing anything is flushing the ATF cooler if foreign materials are found in the pan.