or if you are going to park your car for long periods, push the fresh air in button (dunno whats that called) basta para yung air sa labas papasok? thats the problem of my honda city dati, when left re-circulating air, ang baho the next day, pero mawawala naman kaagad.

also try blasting your fan speed way up when the air con is already off (when you are nearing your home or destination) para mawala yung lamig ng aircon.