Hi, I’m thinking about buying a roof box for my Touran railing carrier. I’m now wondering how big the differences between the individual systems are. I know that fixing one of the main differences is. But assuming the carrier has a good fixing system, how big is the difference between Thule Wingbar, which is supposed to be very aerodynamic, and a simple Thule SquareBar, which is just simple 4-edge steel. manufacturers offer simple steel beams, but also aluminum beams that are mostly aerodynamically somewhat optmized. As said, the extra charge for beautiful aluminium beams is purely from the function? Are they quieter in comparison and consume less fuel, so that you really notice it? You can argue about the optics, but this plays no role for me in the question. Greeting Joker