Patterns and locations of spot-welds and adhesive bonds strongly affect the structural performance of vehicle bodies. In this paper, a rigorous method for designing optimal patterns of spot-welds and adhesive bonds is presented. This method is based on concepts from topology optimization of structures. An adjoint method is used for determining gradients, and a convex approximation method is used for optimization. The method is simple to use and has been applied successfully to realistic automotive component design; it is furthermore robust and efficient to be applied to large-scale automotive structures.