The city car concept has the front suspension and steering encroaching into the passenger compartment, reducing passenger space. If you want a 4/5 seater you really have to move the wheels outwith the passenger space. And once you do that you may as well use the space for storage. A "frunk" as Tesla call it!
Probably makes crumple zones easier to manage too. As battery sits below the floor you need to make that of a size to accommodate a big enough battery for the required range.
If physical size is the priority then your first image (Smart car concept) is the way to go.