I also have noticed a slight whistle similar to what you describe. The noise also appears for me at 4 or 5 fan speed (one or two below max speed). I'll check and see whether recirculate effects whether the noise is present for me. Though I only started to notice it in cold temperatures recently where the auto setting naturally tends to turn recirculation off, so I suspect you may be on to something.Has anyone got this annoyance with their car. With the fan on 4 or 5, and not on recirculate, I hear this wind noise whistle. Does anyone have this noise with their’s?