The new Audi A3 is one example of modern techniques in car body design. The image below shows, in red, an extensive use of hot-formed steel - usually used in high stressed parts with strength in excess of 1000MPa.
The Veloster is an interesting car with one door on the driver side and two doors on the passenger side. How is the structure reinforced to cope with that? Check the picture below, the car uses a "dual centre" roof rail.
The Hyundai i40 is a fine example of a modern car structure. It signals an important trend: by winning the global car body benchmark it shows that Korean manufacturers are now at the highest level in car body structure.