It's aerodynamics and safety combined.

Those bars that you smack into everytime you get into your car and those bars that give you enormous blind spots to hit pedestrians? Yeah, they're there because of safety regulations.

When you put the requirements to be able to roll over and not cave the roof along with aerodynamics, the design constraints are pretty heavy.

Being able to roll without crushing the cabin doesn’t take that much. It’s airbags that are causing wide blindspot inducing pillars and there’s options that maintain good visibility.