Actually Pelka I could be wrong, but I heard that you can make the back windows as dark as you want. It's just the driver and passenger window that have to be a certain percentage (50% here in VA), and less than 6 inches wide along the top of the windshield. Those are the Virginia laws though, which tend to be strict. I had 50% on my last car and it wasn't dark enough. The first time I got pulled, I had my windows down and the bastard told me to put my window up about 6 inches. He slapped the tint meter on my window and about broke it. Then proceeded with a ticket. I also got a ticket for my Thermal exhaust, which was ridiculous.