I use a detail dressing for all black rubber.

 

I masked off the door trim immediately surrounding the door handles as forever black can cause a headache if it gets on your paint (i have heard acetone gets it off though). Regardless, I taped mine off and dabbed it on... turned out pretty well. I then also used it on the window trim.

Originally (note the grey door handles and grey window trim on the front and rear doors)


after using forever black on both... (during window tint)

 

Forever black all the way! I had the same problem and asked the forum and they recommended this fine product. Inexpensive and works! Atlantic British carries this product. Keep your RR looking sharp!