OOPS scratch all that.
if this is on PLASTIC fender well things, and plastic bumpers, then usually a abrasive doesnt work.
you need something to re oil it instead (for lack of a better word)
silicoln waxes, and silicoln tire waxes will put oils back into dry plastics, it wont last long before its back where it was, but it wont do any damage.
------Scratched part-------
if it aint clear coated, and there is some real paint there, "compound" polishing compound will grind the first layer of oxidation off, then a uv protection wax or silicoln wax applied regular after wards.
compound is harsh, and strips off a layer of paint fast, if the oxidation is light, is better to use high abrasion waxes, my favorite (but still harsh) is scotches finish restorer, in the smallish bottle. its high abrasion like "compound" but it has enough good wax stuff to fill in after in one move.
used to be they PUT paint on a car /ubbthreads/images/graemlins/smile.gif now they put a thin layer on and a plastic clear coat, that last about 5 years in the California sun.
before you just scrapped off a bit , with compound, now you re-pain and re clear coat. another fine improvement /ubbthreads/images/graemlins/frown.gif
clear coat doesnt oxidize like paint, it seems to crack fail chip and peel more like plastic.
and any abrasive , even in the waxes is pretty harsh on thin clear coats, and thin paints.
that was a disclaimer, so if you have PAINT like they did in the 80s these lite abrasives are great, if you dont, then the CC and the paint just keep getting highly depleated.
there is a AUFUL acrylic wax, that is nothing more than FUTURE type floor wax, it was called "touchless" it puts a weak soft acrylic clear coat on, and it can make a horrible mess of a bad situation. mabey its good for faking a finish, to sell a car /ubbthreads/images/graemlins/smile.gif