as above, 303 and raggtopp are both excellent...
i also like vinylex, so i am adding it to the list!

 

I use RaggTopp on my 05 S. Two applications already and the top looks great (it's new, so it better look great), the water beads off, and there is NO run off. Also, it was easy to apply (but most products propbably are).

I have never used 303 or any other product. My research brought me to use RaggTopp and I intend on sticking with it for the duration of owning my S.

 

i use the 303, but there are definitely runoff
issues. not only when it rains, but even after i put the
top down which leaves some goo on the back window.
that could be because i apply the stuff rather liberally!