Regarding the rear wheel guards & extended floors behind front wheels, They were more designed around preventing wheel to wheel contact launching cars doing similar speeds on the ovals (Think Ryan Briscoes 2005 crash) & they have worked in that regard.
When you have 1 car driving into the back of a car with a relatively big speed differential as we saw yesterday then there isn’t much you can really do as the wheel guards are not going to be able to withstand that sort of impact.
In terms of this crash it was just very unlucky in that everything happened in the worst way at the worst point of the track.
Taku got sideways on a bump with Dario very close to him & then the angle at which Dario hit Taku’s car & the extra speed he was carrying launched him over the wheels at just the wrong angle to go into the fence at the worst possible part of the circuit.
As to the fence, They are built to FIA specification using the same materials etc… that’s used elsewhere in other categories.
I know that the FIA are looking into new types of fencing but thats still in the trial phase & not something thats been widely used right now.
The biggest problem in these sorts of accidents & the thing which tends to do the damage to drivers is the fence posts. The actual fencing gives which absorbs energy but with the posts been solid they tend to put a big G-load through car & driver & its that which can do serious harm.