The development of new design tools to predict the vibro-acoustic behavior within the vehicle development process is of essential importance to achieve better products in an ever shorter timeframe. In this paper, an energy flow post-processing tool for structural dynamic analysis is presented. The method is based on the conversion of conventional finite element (FE) results into energy quantities corresponding with each of the vehicle subcomponents. Based on the global dynamic system behavior and local subcomponent descriptions, one can efficiently evaluate the energy distribution and analyze the vibro-acoustic behavior in complex structures. By using energy as a response variable, instead of conventional design variables as pressure or velocity, one can obtain important information regarding the understanding of the vibro-acoustic behavior of the system. Moreover, the energy flow post-processing results may be used to tune input parameters for statistical energy analysis (SEA) models. Furthermore, the evaluation of the structural energy and its dominant energy flow paths can assist a design engineer in making design modifications, since the energy flow insights provide a complementary perspective into the structural behavior. The paper focuses on novel concepts of visualization of energy flow distribution, and how it can support in decision making during the vibro-acoustic design phases. This is worked out on an industrial vehicle body NVH case. In particular, different modifications in the mechanical properties (e.g., damping, mass) of the structures are analyzed.