This paper proposes a benchmark problem for the challengers about optimization of body motion control and energy consumption of electric vehicles (EVs) equipped with four in-wheel motor (IWM). By using IWM, not only the control of driving and braking behavior but also the control of the body attitude of EV become possible. In this paper, problem description is given briefly. The proposed simulation platform with full four IWM EV simulator written by Modelica is described and provided. Specially, a functional mockup unit (FMU) of the full vehicle model for connecting between Modelica and MATLAB/Simulink is used for the challengers who are good at using Simulink platform. The challenging problem that includes two subproblems of speed tracking and lane changing is developed, where the challengers are requested to design their own controller in Modelica or Simulink. Example results are given to show the characteristics of the proposed simulator and the performance of default controller in the benchmark problem.