Reasons
Paint does not get on the areas which are already covered with polish, oily substance or wax. The paint tends to break-off from such areas leaving paint-less lines in between. It is due to the texture of these substances which prevents paint to get on them.
Fixing it
You can easily clean such surface, but before doing so let them dry-off. Once the surface has set down properly, you can make use of sandpaper to scrap the area. Make sure to do this with warm detergent water. Now you can apply paint again and get a perfect painted surface.