OK, so I was parking my car and not paying attention (dumb, I know ) and I hit a plastic trash can that was on the street. It left a bunch of scuff marks on my bumper and it looks like the scuff marks are mostly plastic that rubbed off the trash can and onto my bumper. What's the best way to remove that stuff besides washing it over and over again?

 

Until we see pictures we can only help so much, but you will want to start with Turtle Wax's POLISHING compound, i think its the green can. make sure you DO NOT use the rubbing compound, for it's liquid sand paper, literally. work this in with a lot of elbow grease, this should take care of it, based on your description.

if the polishing doesn't work for you, look into Scratch-X and Color-X, both are very good over-the-counter products you can find at any auto. store. work these in the same way.

if that doesn't work, you're going to have to looking into buffing it out, generally speaking, with a Porter Cable dual action polisher. this creates heat when used with a scratch remover to lift a layer of your cleacoat and fi whatever problem you may have, including swirl marks all over the car that inevitably accumulate through washing/drying.

 

judging by my noob experience, i'd suggest clay since it was paint rub off

 

I would go with any polish you currently have on hand, provided its not real aggressive and gently polish in the same direction as the scratches grain. Its a heck of a lot easier to get something more aggressive vs. wishing you hadnt used something so aggressive. Let us know how that worked out!
Or let us know what you already have, and we can go from there!

 

Thanks for the info so far guys. Much appreciated.