legal is 32% on the driver and front passenger windows. if you have back seat windows they can be as dark as the rear glass if you want, which legally you can limo tint the back and rear door windows. window tint on the windshield is illegal below the mark on the windshield, or 6" down from the top if your car is older and doesn't have the mark. I think 20% all around looks great and you can usually get away with it if you just cruise with the windows down. up to you though.