My Renault Clio II has a very streaky/greasy windscreen. It's only apparent in a couple of spots on the glass, but glares in the rain at night. I've tried everything from wipes to sprays and it just won't shift. I'm not very comfortable with driving at night now due to the restricted vision when it streaks.
A friend of mine suggested baking powder and a damp cloth - I suppose as a mild abrasive this might help, but I would like some consensus on this.
What do you recommend to shift a smear that just won't budge?