Tint absolutely protects from UV rays and reduces heat inside the car, but as far as my biggest reason for wanting a dark black tint maily is looks. It adds so much personality to the car. if you can't see through my rear window, you shouldn't be riding so close to my back bumper so you can see ahead of me or have time to react without needed to see what I see. As far as side window's I'm not sure why you need to see where I'm looking. If I'm going to change lanes I have a blinker. If I wanna wave you by at a stop sign I can flash the high beams quickly. If you're busy looking at me to see where I am looking, who's watching the road for you?