Having the AC on in the car on a hot day, and those fans under the wheel blowing ice cold air onto my trainers made with breathable fabric so my tootsies are cool as fuck. Just bliss, really.
I whack mine on to start with then turn it off and just open the windows once the car isn't a death trap sauna with molten plastic steering wheel.
BMW's have this "Max" button which is like being in a wind tunnel. Makes me feel like Arnie as Mr Freeze every time.