back to black is nasty stuff allmost as bad as the shiny cockpit spray silcone based products leave a cheap sheen.
B pillars and black trim behind rear number plate on my cab were well faded, tried back to black sprays came back week later. tar remove the plastic to remove the grime and staining through the years then apply a wax or one of the finishes suggested. B pillars dont need any more prep and i did them 3 month ago still black.