Here's one that I owe my client in a few days. Any suggestions? KeyShot 2, Photoshop -
Nice porsche model!
Truly impressive. Good work with all the subtle lighting from within the house. Have you tried adjusting the gamma and brightness settings? I think a little more contrast would help.
Try setting all your materials to a diffuse white color and render out the scene again. Use this new rendered image as an ambient occlusion pass. Set the AO(ambientOcclusion) pass as a layer above this image in PS and change the mode to multiply. The AO pass is used for shadows and you may have tweak the shader to a slight gray or in PS use curve/levels to add more contrast and bring out more tone. I also like to add some grain, DOF or chromatic abbreviation to help sell the image as being "real".
May I say that you scene is a brilliant one!
These are really good. I am impressed.