I tried one from Lowes by I think Rustolum some time ago on a motorcyle fender and it actually worked just fine, flexed ok and did not crack or peel.
I am thinking of doing one of my DB30 fenders with it just to see how it works on THAT kind of plastic.
Not all plastics are the same material so what works on one may not work on another, worst case is you spent $$ on a can of paint and an hour cleaning it off.