Long story short...
I bought a 4x10 bumper sticker (typical size) and didnt want to adhere it my car, so I also bought a 4x10 magnet you stick the sticker to, then just put the magnet on the car anywhere there's metal.
I've only had it on the car a few months. I took the magnet off a few days ago and I can see where dirt built up behind the magnet and the finish on the car is a bit scratched up. My car is Flint Mica and you can see a 4x10 foggy area on the trunk.

What will I need to do to make this go away? Will a simple wax job do it or will I need to spend some time with a buffer or what?