Here's one I haven't seen anywhere before:

After driving for several hours on a long trip at highway speeds and eventually coming to a stop, there's a distinct odor of hot transmission fluid (not burning, it smells just like new fluid does)either coming through the vents into the cabin, or perhaps now that I think about it, it could be coming throught the hole for the shifter also. It's not around for long (about 20 seconds, then it goes away whether I start moving again or not). There are no signs of leaks, either under the car or in the engine compartment. If I'm driving around town I never smell this - just after driving for a long time on the highway.

Has anyone else experienced this, or have any ideas if it could be the first sign of an overheating tranny? It's still working very well and shifting smoothly with 160k miles on it. I flushed with Mobil 1 ATF 2 years ago, and am planning to do this again next month since the current ATF is now fairly black - but definitely not burned.

Thanks!