Just like everyone else, my Boxster's seat belt release buttons were faded when I bought the car. At that time I applied Mothers Back to Black to the buttons and was disappointed to find that it only made a marginal improvement. The other products that I tried over the next few years were even less effective so I got the Back to Black out again. This time I didn't stop at one application but rather applied it every time I walked by the car (and I remembered) over a period of weeks. Each application only made a small improvement but those small improvements add up so now the buttons look almost like new. I call this a win! - Thought I'd share...
Oh, Back to Black is marketed in more than one flavor. The stuff you want is kind of milky white in color and the package says "for all colors' someplace in the small print.
Cheers- dj