The flat bed is the battery assembly and it doubles up as the chassis. Eg Tesla model S. Some other older models have removable batteries. This car need not have a roof because of the strength of the bed. Your typical sedan must have a roof. You cant cut the roof away to make a convertible just like that. This car does not need a gear box or a differential: Motor-wheel
Its the arrangement of the battery pack that would really be cool to see. I know they use Panasonic high energy density batteries, and also their charging system is proprietary