It choose fat bendy chassis tubes when thinner, lighter straight pipes would make the Atom even quicker. As much as I admire, like and want an Atom, the curved chassis pipes put me off so much - on a purist car they ignore a purist design element.
I also appreciate that 99% of people, and probably 50% of 'engineers' won't agree with it. But why make a car like an atom heavier simply for the sake of looks. Grrr!
At least Caterham et al have the decency to cover the RHS tubing (another engineering purist no-no) with GRP.