I've used a number of things to try and get my black trim pieces back to their original color, but nothing seems to last long. Came across a channel "BleepinJeep" on youtube that showcased using a heat gun on the trim pieces to return it to its original coloring. Seems to have worked out well for him, going to try it on mine at some point. I can understand the concept of why this would work and how the slight reforming with heat on the top layer only would return the proper sheen.
Just food for thought.
Just food for thought.