Just tried 303 on my top the other day.. I went to a DIY car wash today, and OMG the water runs off the top like off a duck's back. Very strange sight to see. We'll see how long it lasts.

 

I use half of a bottle on my top twice a year. Well, I did, with my last car, a daily driver. The new XF is stored almost all the time, I treated it last month when I brought it home - may just do this one once a year.

 

Dear mods, this was not meant to be an advertisement. I have no stake in 303. I was simply commenting, after using the product.