The black plastic fender trim (above the wheel well) looks like it's oxidizing or turning white in some places. Is there a treatment I can put on that trim to blacken it like it used to be?

Thanks!

 

Easiest thing, is to remove it and repaint it with several mid-gloss clearcoats to prevent it from discoloring too much in the future...

Look at using soem Krylon Fusion for plastic, usually found in Walmart and such, works wonders..!

 

meguiars makes a black plastic "polish" i guess for what your talking about. its called "back to black" i think.

 

Yup and works great. I just used it for the first time last month when we were warm enough here for me to do a good thorough washing of the truck.