It was about 2 degrees the other evening and I was driving along happily in the 166 with the aircon on. I took a wrong turn and had to double back, and in my frustration red-lined it in first, second and third (nothing like a howling Alfa V6 to make you feel better!). However, the car then started to mist up even though the arcon was still on. I pressed the demist button to redirect the airflow to the windscreen and maximise the fan speed, and while this helped a bit the windows were still not clearing as quickly as they should. I switched the aircon off for a few seconds and then back on and this seemed to fix it.
Does anyone know what might have caused this? Could the high revs have tripped something in the compressor? I haven't noticed this happening before, but it might just have been more noticeable this time because of the cold temperature outside.