I bought a 2001 SE in July and have put about 9,000 miles on it since then...I drive another truck for work and only drive the Xterra on the weekends. I took it in to get an oil change and they said the AT fluid was gunky and needed to be changed. They said they do it every 3rd oil change or so. Is this legit? The dealer has a great rep in this area and I know a lot of people who have bought trucks from them, but I drove a Honda before this and the AT fluid only got changed every 30k miles at the major servicings. Thanks!