Put the rattle can stuff away.
This is what I would do. I’ll list it in a step by step so there is no confusion.
1. I would buy some kinda polisher. This will be a tool that can spin fast. Not the slow moving device you use to wax a car. Here is a cheap but good one from harbor freight. If you have a air powered die grinder, they sell buffing attachments.
https://m.harborfreight.com/7-in-10-amp-variable-speed-polisher-62861.html
1.A get the pads for polishing and buffing.
2. I would get a polish and a buff, this is your choice,there are tons of options. 3m sells stuff, maguires 105-205, the parts store will sell stuff.
3. I would slowly polish the area, then buff the area.
4. Check to see if the problem is fixed. If it’s real real close , leave it be. If not, then move on to step 5.
5. Tape off about 1” around the area to protect the good paint. Using a sanding block and lots of water, slowly and carefully wet sand with 2000 grit until the area looks mostly dull. Be careful, if you start seeing color , your into the paint and now need to have a professional paint the fender.
6. Repeat steps 1-3.
At this point the area should be shinny and new looking. Add wax and be happy.
If you already own a buffer and polish what what bit, this will be a cheap and easy fix. If you don’t, you’ll speed around $100. OR For $100 you can have a body shop buff and polish the area. For $100 you can also have a mobile detail shop guy buff and detail the car . Call any car dealership and ask for the pre owned manager or reconditioning manager , tell them you need a good mobile detail guy and they will hook you up. The going rate for a detail is $100-150.
THE RATTLE CANS WILL MAKE IT WORSE!