The complex geometry of the engine room of a passenger car has been modelled two-dimensionally and the thermal and fluid flow therein have been analyzed by using a commercially available code, PATRAN/FLORAM$mid$N. FLOTRAN adopts a finite element method with streamline upwind formulation for convective terms and the k-.epsilon. turbulence model to solve the three dimensional turbulent flow and heat transfer problems. Velocity vectors, pressure and temperature distributions have been obtained for various cases with different arrangements of license plate, underbody-covers and air dams. The results show that the numerical analysis using PATRAN/FLOTRAN can predict qualitatively well the practical phenomena.