Can be the final sanding, bad metallic coat or bad clear coat. Sometimes new looks good, then when paint dry further the putty sorts of sink and the sandpaper lines appears also.....What can I say. Just some under tree (bengkel bawah pokok) paint shop. I know the paintjob sort of suck when the roof paint looks weird despite using metallic paint. From far, the surface doesn't reflect nicely, it has that sort of dull feeling.