This paper discusses the collapse behaviour of vehicle structures under quasi-static loading conditions. The finite element limit analysis for three-dimensional structures is formulated based on the duality theorem in plasticity. The analysis considers sequential deformation of structures with work-hardening effects. The collapse analysis for an S-shaped frame is conducted using both the limit analysis program developed here and the commercial code ABAQUS. Results show a good agreement in load-carrying capacity and deformation mode predictions. Example studies also demonstrate that the method presented can be used to identify the weak part of a structure and change its design to enhance the load-carrying capacity and reduce vehicle passenger compartment distortions.