This paper covers an application of integrated computational materials engineering (ICME) for third generation advanced high-strength steels (3GAHSS) to vehicle light weight body structure development. Following a brief overview of the ICME project, design optimization of a vehicle body structure using a multi-scale ICME material model is presented. Preliminary results show 30% mass reduction potential of a mid-size sedan body side structure with the use of 3GAHSS. Design optimization steps, as well as the challenges in application of ICME models in vehicle design integration and optimization are addressed. The paper concludes with integration steps that are needed to enable vehicle performance metrics driven material development in terms of chemical composition and phase characteristics.