A procedure was developed to model the vehicle side impact response. This method uses rigid segments to represent the important structure components such as the door, the upper B-pillar and the lower B-pillar. These rigid segments were connected by joints and spring-damper elements. The moment-rotation and the force-deflection characteristics of the structure are obtained by conducting component tests. Two CAL3D models were constructed based on this approach for a two-door experimental car; one simulating the baseline design and one simulating the modified design with a modification to the R-pillar and the addition of padding. Parametric study indicated that lower TTI and pelvis acceleration found in the modified car were due to the lower B-pillar enhancement. The padding used in the modified car only has a marginal effect. Parametric study also indicated the lower A-pillar enhancement reduced TTI. On the other hand, the upper joints did not appear to have a significant effect on the occupant impact response. The changes in structural and padding parameters in this study were simulated without regard to other constraints such as practicality and manufacturability, and therefore specific designs may not be realizable.