Yup, you can get ANY percentage on the back windows and the rear window.
You can only get like a 4" strip or something on the front windows or windshield...aka GHEY.
I have 35% everywhere 'cept my windshield, so it is not too dark. I parked next to two state troopers and right outside where they were sitting eating. I'm sure they saw it but they were eating lunch so I just walked past them, got my food and left. I drive in Ohio most of the time and they actually have police but so far no one's cared, but I don't look like a banger.
