I know it's not painted - you can still buff it out with a light compound and wax. I polish molded plastic all the time.
Scuff on rear bumper
If you can live with it - do so. You could pay for an expensive repair and some numpty could do the same thing again the next day. When the time comes to trade-in the car or sell it, the chances are you will have picked up a few more dings by then. Get them all done in one visit to a reasonably priced body shop
