After reading the tests in Autoexpress of Anti Mist potions I thought I'd try the winner. Surprisingly it works very well. Easy to apply too. I bought from a internet site that was offering a 3 for 2 on Comma glass treatments so I still have glass scrub and water repellent to try. It'll be interesting to see if the water repellent is better than Rain X, I won't be using on the windscreen though just side windows, mirrors and headlights. Wonder if the glass scrub can remove Rain X? Last time I had to use cerium oxide to get it off the windscreen.

I find RainX on the windscreen, windows and mirrors to be fab. Trouble is it doesn't last very long

I have used Rain X on the windscreen in the past but I tend to find it distracting when it drizzles and the wipers smear. Halfords own brand won the water repellents test.