restoring faded rear plastic side panels

900 dollars for a dart part that isn't correct for b'cuda , then the chromed plastic trim pieces sold separately. That's a lot of incentive to make the correct originals look new.
They should match the doors. Below the trim is a lower gloss like the vinyl. Above the trim a medium high gloss like the painted section of the door. OK they match the door painted metal again at the bottom but I wouldn't be highly concerned with the finish down there. Very little of it shows. I don't know that they used 2 different paints though. The texture or lack of would create 2 different finishes to the eye.
I found a way to use the stainless trim piece form a door on the rear panels. One piece from either door cut in half is enough length to do both rear panels. The OEM plastic never exactly matched the stainless anyway.
A lot of labor in modifying this piece of stainless. Not for everyone I'm sure.