The Multi Material Lightweight Vehicle (MMLV) developed by Magna International and Ford Motor Company is a result of US Department of Energy project DE-EE0005574. The project demonstrates the light weighting potential of a five passenger sedan, while maintaining vehicle performance and occupant safety. Prototype vehicles were manufactured and limited full vehicle testing was conducted. The Mach-I vehicle design, comprised of commercially available materials and production processes, achieved a 364kg (23.5%) full vehicle mass reduction, enabling the application of a 1.0-liter three-cylinder engine resulting in a significant environmental benefit and fuel reduction.This paper includes details associated with the mass reduction and structural performance of the multi material body in white (BIW) relative to a C/D segment production vehicle. Selected stiffness, durability and crash requirements are assessed. The structure incorporates aluminum castings, extrusions and sheet as well as steel sheet, assembled using structural adhesive bonding and a variety of joining technologies. No other body structure in high volume production incorporates this combination of materials and joining processes.