Abstract: An automotive vehicle comprises a frame having a pair of side rails interconnected by a plurality of cross members. A rocker panel substantially parallel to and spaced from each side rail creates a gap. An energy transfer member seats within the gap for transferring energy between the rocker panel and the side rail in a side impact event. The energy transfer member is sufficiently stronger than the side rail such that impact energy deforms the rocker panel and travels through the energy transfer member to deform the side rail prior to any deformation of the energy transfer member, thereby maintaining the gap to reduce side structure intrusion into an occupant compartment. An accelerometer mounted within the vehicle inboard of the side rails senses vehicle frame acceleration, and activates a vehicle airbag system as necessary.