Yep, we played with it a bit. Problem is, not all metallic is ferritic, and the painter can defeat alot of the effect simply by the angle they hold their gun (or how often they "touch up" that area). We got it to work, its simply putting a flexible magnet (cut to a shape) under the part and spraying over the top. Most flexible magnets aren't strong enough to make the image obvious, and the effect isn't very clearly defined. Remember these toys?