As energy and environmental protection become increasingly important global issues, a lot of efforts have been put into lightweighting vehicles, as the reduced weight of a vehicle attributes a lot to the efficient use of energy. According to statistics, a 100kg reduction in car weight can translate into a 10% increase in driving mileage and a 15% to 20% decrease in power costs. It also helps reduce carbon emission. These factors drive the automotive industry on a quest for innovative materials and material systems that help make vehicles lighter.