I did a lot of research on this before having windows tinted in one of my cars. I live in Indiana and the max is 30% all around, nothing on the windshield. Any reputable installer will not exceed the state standards. But the interesting thing is that during my research I learned that the police can make you remove anything darker on the spot, and have done so many, many times. They seem to target younger, more agressive drivers when doing so. So when my son was being insistent on getting 5% on his Integra, and doing it himself, I refused to let him. He eventually listened to reason and we got him the 30%. He likes it now and there are no worries about him having to scrape it off during a traffic stop. I have him keep the receipt in his glovebox to prove it's 30%.