Hydrographics or water transfer printing allows for the application of printed designs onto 3D surfaces. This video shows a series components including wheels, plastic moldings and even a whole front quarter panel being decorated with hydrographics. The graphics can be any design you can imagine as they are printed, so anything from technical patterns to wood grains can be applied to the part. Even text is possible.
The process in this video is manual but it can also be automated for mass production.