I don't have any glass cleaner and my cars blocked in atm so can't go out and get some.
Would a damp tea towel do the trick?
Don't use household window cleaners, they leave a film and it'll make headlights glare through it.
Use a proper car window cleaner, it much improves the quality of your view at night and will usualy stop it steaming up so easily.
Autoglym glass polish is what I use, it's great.
I never have issues using household glass cleaners.
Just never use it on windows which have been blacked out, will mess it up.
I've heard of people using newspaper.
I just use Windolene and kitchen paper myself.