I still think that if it was anything internal to the engine, I would smell fuel or oil or coolant, but it's none of those. It's as if the AC has a loose connection, and under a moderate acceleration, the freon makes its way to the passenger compartment. There is no change in performance, no sound, nothing--just a simple, rather nondescript smell that lasts for a few seconds.
I guess I'll just see if anything else comes up.
BTW, it's happened both with and without a passenger, so I don't think it's the pants-crapping theory
