You’re probably right, it’s more about aero + production constraints. I don’t think the concept cars use the same constraints, which is why they have to change to get to production. Even if a design looks different and is still aerodynamic it doesn’t mean it can be economically produced without large changes to the production process.

I’ve only worked in body panel stamping in automotive assembly as a controls engineer, so I may be taking a bit out of school here.