Hi, I also responded to you over support, but here is my comment:
The lighting in this image is correct. Corona simply calculates it based on the HDRI you are using. It is pretty contrasty (bright sky, darker ground), but you can already see that the result is realistic, since the real-life objects in the background also have strong, dark shadows, same as the car. To make shadows brighter you can try changing the materials (making tires brighter or more reflective), or you can alter your HDRI in some application such as Photoshop, or use the map's output settings. You could also try changing tone mapping settings in Corona's VFB such as exposure, highlight compression, contrast.