I have recent gave this a try after Dom (one half of Dodo Juice) recommended it to me.  With the weather in Scotland not being the best only within the last week i got to use it.  Very easy application if you follow the instructions (at first i didnt and found it hard work), but I used a makeup pad to apply, then as per the instruction as it started to thin out, go back over the worked area as a "dry" application then buff it off (used a blue MF which i got with my DJ SN Metal polish).  Really simple and quick to apply.  There has not been much rain since applying it until today so perfect oppertunity to get a video :)

http://www.youtube.com/watch?v=2amxGYNn0Zs - http://www.youtube.com/watch?v=2amxGYNn0Zs

I know there are the likes of G-techniq and Nanolex and not sure about their ease of use, but this was very simple and as you can see its effective as well :)