Hello mate. Not sure about this one but I had something similar happen to me on the way down to No Rice a couple of months back. Scared the life out of me cos it steamed up whilst the rain was persisting down and i was in the outside lane of the A3. My A/C isn't working very well so it took ages to clear. How long ago did you put the hoses on? Are you loosing water quickly and is your heater blowing hot? If you had put a pipe on wrong I don't think it would work properly. Check your footwell carpets for damp. Mist on the inside can sometimes be a sign of a faulty/leaking heater matrix or