Yes it does. Obviously not for big crashes. The screws are positioned at roll over touch points, and if the car rolls, because the screws stick out for 1-2mm, the body is slightly kept from the ground, so reduce the cutting into the lexan plastic by the ground. It's just a small but extra protection.
(and I guess it looks cool on top of window too.... )
I used Zen front and back. I tried exceed too, use hard front, and soft or medium back, and only tyre water at back. However, zen combination is much bette.