The immersed boundary method (IB method), which combines an LES method with the law of wall (two-layer model) and local mesh refinement, was applied to the flow simulations around shapes of a vehicle. It was confirmed that the calculation results of the proposed approach showed good agreement with the experimental data and achieved short turn-around time owing to considerable reduction in time of the mesh generation process. Consequently, it was found the proposed approach is quite useful especially for the early stage of a vehicle development process.