This paper describes the design cycle of the permanent mold A356-T6 cast aluminum front and rear suspension crossmembers of the Fifth Generation Corvette. The cycle starts with the definition of requirements followed by concept development and mainstream selection. A design/analysis loop is undertaken to optimize the design before the construction of prototypes. The prototype crossmembers are then tested in the laboratory and in product assurance vehicles. The empirical data is fed back into the design loop to ensure that the final production release of the crossmembers meets the Corvette's performance objectives. The program business case, engineering specifications, and manufacturing processes all contribute requirements that must be satisfied by the design of these components. The most challenging design requirement was to design crossmembers with the least possible mass and the highest possible stiffness.