Try adding a matte effect for the tyres cause now they're too much reflecting. For the shadows, you can usually set the intensity of the shadows somewhere, or if you used Global Illumination, there should be another function called Ambient Occlusion or something like that to be added as an effect to the floor texture (judging from C4D, like I said I don't know how it is in Blender. But with the white floor, the shadows are a lot better already.
Next step you could do is try to find a free environment or try to build one from scratch and add lights from different angles, with different intensity and colors. That's a bit playing around what looks good and what not.

GPGSL : Team Owner of 'Maverick Track Performance' (MTP)