Yeah I know what you mean about the paint work.
I'm happy with the rear mudflaps.
But first I think it's better too relieve the mudflap sharp edges with a fine toothed file or abrasive paper then fit some clear plastic vinyl protector to the bumper/mudflap contact area, (similar to the stuff that comes as standard on the leading edge of the rear arches).
After that I think you're good to go.