how do you keep the interior of your car's front window clean?

the vinegar is going to be your best bet for home remedy or go buy the rain x brand interior windshield cleaner its anti fog and coats your window. it like 5 bucks

lol, I have to clean that film from our van all the time. I havent done it to it since its new still, but all my other cars I used Rain-X that you rub on and wipe off, like a wax for your windshield, it can be used on the outside too, so you never have to use wipers again, it wont fog at all and the water beads up.

I remove the dry dust and film off the inside of the windshield with a clean dry terry cloth. If this doesn't work for you, use windex to clean it, thereafter use the dry cloth .

I Use white vinegar and newspaper, the paper seems to stop the smear and the vinegar is great for removing the gunk without leaving streaks.

Just crunch up the newspaper sheet and apply vinegar to the paper and wipe until clean and dry.

white vinegar and water ,use terry cloth to wipe it clean.