We have a really annoying problem with tenacious condensation on the inside of the glass of our 5k mile 2 year old Fabia in some winter conditions. Internal condensation in winter isn't surprising, but this is different. Steps have been taken to minimise moisture ingress and water leaks past the door seals have been fixed and there's now no evidence of leakage into the car, but the problem persists. I wonder if moisture-laden air is diffusing into the car from the air conditioner evaporator, but that's not the real problem. Quite large water droplets form a film that clings to the glass with such tenacity that wiping just spreads the droplets around without removing them, or creates a water film that runs down the glass. It can take 10 minutes for the heater to clear this condensation. When this occurs we have to abandon the Fabia and use the condensation free SAAB standing next to it on our drive. There seems to be some sort of contamination on the inside of the glass that I've been unable to remove with all manner of aggressive substances from strong detergent to body shop cleaning solvent. I wonder if the dealership's valeting has contaminated the glass with something.