OK To each of its on. I want to do this because the sun it's bad sometimes it blinds you. So installing this on my truck it's a safety thing. But nit that curved.
I totally agree; the darker the tint, the less light gets in. I used 20% to stay consistent with the window tint on the rest of the car and I was personally happy with the length, it was long enough so that I could conceal a radar detector and dash camera which is why I tinted the windshield in the first place.