Until recently I was a rain repellent Virgin, I had my car professionally detailed and they applied Rain-X to the windscreen. I was amazed with the results. At motorway speeds the rain sheets off the windscreen and there is no need to use your wipers. You save money on wiper blades, have better visibility and less driver fatigue in the rain. The heavier the rain the better. Below is a video of what it did on my car.

I have since bought Rain-X and use the top up fluid in my washer bottle with distilled water. I have been told there are other rain repellents that work at lower speeds but I personally have not used them.

The application is easy. Clean the glass completely and apply with a microfiber to a dry windscreen. Once its sat for a few minutes buff if off with a clean microfiber cloth. It lasts about 3 weeks weather allowing.

Pardon the music. The rain was absolutely bucketing down to the point where previously you would need your wipers on fastest setting.

http://www.youtube.com/watch?feature...&v=Tdux6flaiGs