Plastic Rocker Panel: Paint Stains

[RB2]

The car is silver and the plastic rocker panel is black.
Looks like paint has been oxidizing and depositing on the PLASTIC black rocker panel over time and after each rain, etc.

I took some paint thinner to the plastic rocker panel (photo 3) and it seemed to mostly swirl it around a bit without making much progress on the clean front.

Any advice on how to get the paint off and then a product recommendation on making the black plastic rocker panel shine or restore its blackness?

 

[embolism]

to clean you can try a magic eraser or APC and a scrub brush

for lsp, sounds like another job for Ultima Trim and Tire Guard
It's expensive but it's the best. Second choice would be Poorboys trim restorer