Having looked it over a bit, I have some comments.
They have the right idea. Reduce mass and friction.
The weight, 450 kg is good, but the car could use some extra features even if the weight increased by 25% or so. Like side doors, for example.
No doors on the side! ????
A bit too tight for comfort.
However, all things considered, it looks like the wave of the future in cars. Today's cars are just too heavy to be practical for much longer with the continual rise of fuel prices to be expected for the next few decades. It will be a pleasure to see the death of the SUV craze.