That'd make the car stink to high heaven.
It stands for Water Displacement 40.
Water wont settle one it, rub it into your window (not enough to make it smell) & it will stop fogging.
That'd make the car stink to high heaven.
clean your windows.
Steam has less to cling to if the window is clean.
also, get something to dry the car out on the inside, like a dehumidifier tub or a old sock full of rice.
I'll have to give some of these a go, I've been having to de-ice the inside of my windscreen when it's been really cold.
seriously try the washing up liquid. It works wonders, if it doesn't just reply and slate my advice. It will cost you nothing but 5 mins of your time.