Sounds like it might have been caused by harsh cleaning products that have reacted with the gloss plastic trim and etched into the surface. Quite often, the black plastic wheel bolt covers on the locking wheel bolts will take on a faded appearance if an acid based wheel cleaner has been used.
If you’ve only just got the car, it’s unlikely you’ll know what products have been used to clean it. If it’s been treated to a regular cleaning at one of the many Eastern European hand wash places, then it’s likely harsh products will have been used. Time is money to those places, so the quicker they can remove the dirt, the more cars they can wash which equals more ££££‘s.
I was gong to suggest Gtechniq C4 Permanent Trim Restorer or Gyeon Q2 Trim, but as you’ve already tried one of these, then a plastic trim / dressing product might not give you the results you’re looking for. Machine polishing would normally help remove etching but as the parts on your car that need attention are likely to be very difficult (or impossible?) to access with a machine polisher, then that probably isn’t an option. You could try hand polishing with an appropriate cutting compound. Sorry, can’t help with the part numbers, but hopefully there’s a forum member who’ll come along soon who can.
