My 1995 black top needs something to brighten its look. Deeper black, etc.
Ray

 

Try this product combo. It's what I use and the cleaner alone can really do a nice job in removing imbedded grime.

http://www.topoftheline.com/ragcleanprot.html

Anthony

 

I just put this on my BoxsterS top (like five minutes ago) in the garage. Works very well. The cleanser is the only thing other than water that I use on my top to clean it. I use the oxo feathertip brush blot it dry and then take an old shoe box and placet it over the spray can to keep the mist from getting on the paint. I usually do several coats after each dries fully.

as far as dye there is a product called marhyde or something that people use on their faded fabric seats. I'm not sure if its water proof though.