I am curious about successful and cost effective button replacements for the fan buttons.
That is the one adjustment I make, especially for a long period where IHKA -> OFF_MEMORY was not coded on my car.
Generally, when I'm short tripping on work days to my commuter train station I have IHKA off, unless conditions (number of occupants, outdoor temp) causes my windows to fog. I'll then turn on one segment of manual fan at, say, 17C.
On longer/normal trips, then I'm full AUTO.
My driver's side fan button has one failed spot in the little fan logo. I'd replace it if it was easy.
