"My wife recently purchase a 1996 Mitsubishi 3000 GT that has factory built tinted window that are dark . Do we need to replace these window to be legal in Illinois? Thank you for your help."
Thanks for your question. The only factory tint that is usually on windows is that which is allowed by law, at the top-most part of a windshield. Otherwise, the tint most likely was applied after-market. A good film tinting job will appear to be part of the window, but it can be removed. There is no exemption for tint when it is on a car you purchased. It is up to you to bring the vehicle into compliance with the law. When you are preparing to purchase the vehicle, you might bring this up as a point to the seller.