Not sure what its called, but I remember in an S2000 promo video that one of the vent settings was for the "enjoyment of top down driving in colder weather". Its the one that shows the air passing through the cabin via the vents right above the stereo.

I noticed that when I use that setting, my fogged up windshield de-fogs pretty quickly, as if it was on the windshield setting itself, leading me to believe that the A/C compressor turns on like a de-fogging function. But I don't hear it kick in. Am I missing something?

 

not sure what one it is but it is listed in the manual if you got it

 

I am fairly certain that the A/C compressor does not turn on when using those vents.

 

Only if you hit the button. Only time it forces ac is in defrost

 

^This. Compressor is only used for those vents if you hit the AC button.

Probably because it's bringing in air from the outside. Depending on conditions, outside air can help with defogging.