I had the paperwork from my original installation saying the tint installed was 50% on the fronts and on the other i just called the cop and told him I had it fixed and asked if he'd dismiss it to save me a morning off from work. He did
Just be nice and respectful when you get pulled over and when you call. I played the dumb card both times saying, the tint shop told me that my factory windows have a slight tint in them which causes the darker reading.