Honestly, FIA, put F1 cars inside a kevlar reinforced bubble. That should do it for safety. Because the drivers definitely don't know the risks they take for the paychecks they're getting. Or here's another thought: why not use that shield material for the helmet visor, and actually make helmets from something beside styrofoam?
I know your post is flippant, but the material of the helmet is irrelevant here. At the speeds they're going, it doesn't matter; if something like a spring hits your helmet you're going to be in very rough shape. In that small of a space, it's impossible to absorb the force of impact without it getting to the drivers' heads. The shield means that those objects simple don't make it to the head and eliminates the problem entirely. Also, with a shallow angle like in the images, the object will be deflected away from the car; so the material doesn't have to be that strong, since the force is deflected.
I'm all for the shield. The halo was a moronic idea that you'd have to be stupid to support. The whole reason these things were even in consideration was Massa's accident, and the spring would have still hit him in the face if there was a halo on his car. Aesthetics aside, it just wouldn't do a damn thing.