In CT 35% is legal on all windows, and you can use whatever you want on the rear windows, as long as the front windows are 35%. They don't even give you a ticket anymore, they give you a warning and you have to have your car inspected at motor vehicles so they can check to see if it's a legal percent tint. I have heard that 35% is legal everywhere, if not, why would they have factory tinted windows on cars, even on the front windows? The same way the clear tail lights were illegal, until the new lexus R330 came out with them and they said there legal as long as you have LED bulbs. I've seen NY state troopers with all windows tinted so I assume that it's legal to have a certain %. Call your local public official, I'm sure they would tell you what you can have. That way if you get a cop who is bored, you can go to court and throw it in his face, not that he'd probably show up, seeing as they don't show up for speeding tickets.