The mailboxes look fine. For me it looks like a road that's there but covered my a high curb or is a little slanted. And what I and probably most of us did was use the clone tool in Photoshop. You select the Clone Stamp Tool press and hold ALT and with your mouse select the part of the picture you want to sample and click then let go and draw over what you don't want. Takes a bit of practice to make it look natural but its worth it.