The car has these flat black pieces behind outside mirrors and also behind the rear windows (small triangular). Mine are really losing their luster over time, and I am wondering how to make them look good again.
use this stuff myself. just what you're looking for.
As your ride's exterior ages, rubber, plastic and vinyl exterior hardware of all colors will dry, crack, flake and deteriorate. This oxidation can be stopped and reversed with Mothers® Back-to-Black®, our favorite auto-care concoction. This trim treatment is great for all sorts of exterior hardware in all colors-bumpers, molding, louvers, window trim, vents, seals, skirts, door handles, wiper arms-anything that's plastic, rubber or vinyl. Apply Back-to-Black® to sun-burnt plastic, rubber and vinyl to revive the factory-new sheen, then re-treat that exterior hardware regularly.