Having finger nail scratches at the door handle area is a common and unavoidable problem to most of us. Though I am very careful whenever I pull the door handle, but my passengers might not be. This resulted finger nail scratches at the door handle area on all of the doors, besides the driver's door.
Those scratches could be deep or shallow. As we know, that area is unreachable by machine, so working with hand is the only method. When it comes to removing paint defects by hand, the first hand polish in my mind is the Meguiar's Scratch-X. I get good results by rubbing Scratch-X with a piece of Meguiar's Hi-Tech Foam Applicator.
The other permanent solution is to tell your passengers to be extra careful whenever pulling the door handle, but of course this should be done in a very polite manner. Not all people could accept such words, so think before you say!
Below are the "before" and "after" pictures of the Accord's door handle. Due to the nature of the colour, it's rather hard to notice the scratches, but if you see it carefully, it is shown on the photo.
f=85mm, f/8, 1/200s, ISO200
f=85mm, f/8, 1/200s, ISO200
Canon EOS350D, EF-S 17-85mm f/4-5.6 IS USM