[doikor]

You don't need a cage if you don't go racing. Also the single piece carbon body may be strong enough to not need a cage.

Though convincing FIA of that fact is going to be really hard so probably easier to just weld one in there if you want to race it for some reason (and find a racing series that would accept it)

edit: And a cage without a proper racing harness and a helmet (+ HANS device) can be really dangerous.