Nissan is just like all the other automakers who want to reduce mass for better performance and fuel economy. The GT-R is a mix high power to low weight. Most of the GT-R structure is made from high strength steel. Parts include the front and rear lower rails and the A-pillars. Ultra-high strength steel is used inside the internal structure of the door to increase occupant safety. Look at the images below to see the structure and where different material is used.