Nissan X-trail Transmission Dilemma

[offroadfan]

I own a Nissan X-trail 2005, 2.5 with automatic transmission. Last month I made the 40,000 km/24 month maintenance with 46,716 km marked on the board. The owner?s manual indicates that the automatic transmission fluid has to be replaced at 40,000km, but my Nissan-approved customer service advisor told me that because the X-trail already exceeded the 40k?s, the fluid shouldn?t be replaced. He recommended me to not replace the fluid before the transmission needed proper disassembly and mechanical work. They stated that they can replace the fluid at my request, but they would assume no responsibility if the transmission breaks up or starts having problems. I would perfectly understand that, if the X-trail had 100,000 kms, the fluid shoulnd?t be changed and the wise thing to do would be just to wait for the transmission to break. But, does an excess of "merely" 7,000kms makes a difference on whether I should consider the reasonability of changing fluids? I found it strange, therefore I asked to a mechanic who works at the Nissan-approved service provider and told me that if it were his car, he would change it, but since the Nissan customer service representative recommended me not to do it, the mechanic told me that probably it wasn?t unwise to simply wait for the transmission to faulter. I was shocked when I received such an answer!. I asked again to other people but I didn?t receive a rock-solid, conclusive recommendation. I do not trust the recommendation made by the Nissan representative: the place where they ought to know everything about Nissan cars from A to Z wasn?t able to provide me a solid recommendation without hesitating. I bouth my Nissan X-trail brand new around 30 moths ago and right now my Xtrail has around 48,800 km, but I still have the dilemma on whether it is or not wise to change the transmission fluid (like the manual says) or just to wait for my transmission to faulter, as my local Nissan customer service recommended me to do. What should I do?