I have 20% all around except for the front windshield. i've gotten pulled over 4-5 times since I've had it on and the only time I got a ticket was from a state trooper. I had to take the tint off the front two windows and show the car at the local precinct. later that day I went and got them re-tinted.
i believe there's a tint shop in michigan that will re-tint your windows for free if you get a ticket. wish i would've known about that. but the 20% is pretty decent although I would have liked something darker.
