I think I read that only a couple of layers will have an effect, above that won't do much. Is that right? I'm doing my 2nd layer of the all finish (AF?) paint protector this weekend. Wondering if I should try something else to top it off in a week or two, or keep on going with this a few more times. I don't know *squat* about the chemical properties of these things and how they bind to the paint.