I have read great thing about vinylex but I have also read (also going to buy) 303 Aerospace Protectant is far better it has a SPF rating of 40. Do a search on
www.autopia.org for both product and read the reviews. From what I've read and researched 303 is slightly better.
A little something about 303
http://www.autogeek.net/303aerprot.html
and a little somthing about vinylex
http://www.autogeek.net/lexsprayvin.html