In our collection of toys

is my convertible, and the top is about 2 years old. I think it should be blacker than it is.
There are a few existing threads that talk about
cleaning, but i am looking for a
protectant and/or repair type product that works similarly to Mothers 'Back to Black' but for fabric.
There has to be some people around here that have experience with convertible tops, and maybe tried different products over the years. (not brand new NBC's)
Any tried and true?? (OR, what NOT to use?) I am a loyal ZAINO fan - unfortunately, they don't have anything (yet) for this application.