For those with 05-07 Pathfinders, if you haven't changed your transmission lines to run through an after-market external transmission cooler yet - might want to do it quick.
Do a search on the net and you will see how many folks are having issues with the factory lines deteriorating within the radiator core. This leads to antifreeze heading into the tranny, and tranny fluid into the cooling system.
One early symptom isn't actually the transmission having issues - it is an apparent lack of cabin heat with the engine up to operating temp. Then some transmission 'shudders' then complete failure.
$4000+ to have fixed at Nissan, and they won't typically want to help anyone out. Known issue, tons of stuff on the net about it, but no factory action yet.
Friend of mine is going through this now. Same tranny is in the Frontier, Xterra, Pathfinder, and even some of the cars in the Nissan/Infiniti line. The Pathfinder is the only one with this cooling loop issue AFAIK.
Usually fails around 70-80K.