Just like tabsscale1 mentions, it is the humidity. It can be fixed easily, just use a bit of wax on the clear and it will disappear. Better yet, get some 1500 - 2000 grit sandpaper, wet sand the model being very careful not to sand away on the details, corners or emblems. Rub it with some rubbing compund and then wax it. You will be amazed at the shine.