It's WAY more visible if you are wearing polarized sun glasses while u look at it. I thought it had gonne away by tinting my windows too, but after my gf bought me some Oakleys, I found out it was still there. It has something to do with the refraction of light between two mediums with different indices of refraction. Glass, plastic, glass makes it refract, so adding another layer of plastic (tint) makes it appear to go away. Adding yet another layer of glass (sun glasses, polarized to boot) makes it come back.
Al