Champion Motorsport faced a design problem when they began the process of creating their highly specialized turbo intake system for the Porsche 997. The part had to be both technically capable and pleasing to look at, but standard casting processes meant one or the other features would have to be compromised. So the engineers at Champion turned to additive manufacturing and 3D printing to build their high-end engine parts. You can read the whole story here: http://3dprint.com/36120/porsche-997-3d-printing
Below is a photo of some of the parts made for the Porsche: