This thesis project is aimed at analysing innovation related to car body structures. The need to reduce pollutant emissions to meet more stringent environmental regulations, together with the need to ensure vehicle safety and high performance, has led to the development of new materials for the car body: from advanced and ultra-high strength steels to new aluminum alloys. The introduction of multi-material structures has paved the way for the development of joining technologies that allow different materials to be joined together. In this thesis, the main innovative joining technologies for multi-material structures are analysed and an activity is carried out at the “Centro Ricerche Fiat”, where a riveting process has been analysed using Self-Piercing Riveting and considering a specific combination of different materials..