Yeah, I didn't have much luck with it. It stays wet, so although it helps with water, it also holds on to dust, and at that point all you can do is wipe it off and reapply. The aero-effect on the rear camera locations means they're constantly getting hit with grime. In the precautions section, is says not for use on non-glass surfaces; the camera lenses, but there's really no definitive information on what the current lenses are made from. HW3 was polycarbonate, not certain about HW4.