Re:
As you probably know the UV knackers Yellow and Red solid colours, flouro paints especially, so try a proper cutting compound on a pad or microfibre cloth or worst case elbow grease and T-Cut with a cotton rag.
T-Cut is a very very light cutting compound and requires a fair amount of effort, you want to be taking a few microns of paint away to reveal what lies underneath, sometimes they are too far gone but you've got 50% chance of success.
Then cover with wax or polymer polish.