Windows steam up in rain WHY?????

[Bluefox]

Good clean and rain-x anti fog?

[Uruk Hai]

I have used the anti fog and I thought it was great to begin with but I was driving home one night and the inside of the screen was just running with water and it was all I could do to stop it running down the back of the dash. I don't know why this happened although I have an idea that the anti fog sort of soaks up the condensation and after a while it just stopped working so I stopped using it and haven't had it happen again !

[Uku]

aye thats the problem i had , the rear passenger footwell used to get very wet when it rained overnight. it ended up being one of the pipes from the sunroof channels had blocked so the water overflowed the sunroof channels and ran down the inside of the body into the footwell , there was no signs of damp from the path it took from the roof down to the footwell as i think it ran down the inside of the plastic cover where the seatbelts are.

[gybjw]

Is it not just the effect of your breath being warm and the windscreen being cold from the rain = it steams up!!!

Mine will start to steam up in the rain and I'm pretty sure there's no leak. Just put the fan on and open the window a little.