I know some of the components at SpaceX are manufactured using metal additive manufacturing (3D printing), but how much of the entire Falcon 9 launch vehicle or Dragon capsule is made up of printed components? Obviously there are more sensible techniques for manufacturing parts like thin-walled panels, but how much of the vehicle could potentially be 3D printed? How about an entire engine?
Note this question is regarding all variants of the Falcon 9 and Dragon capsule, and I also welcome any relevant information about test hardware like the Grasshopper.
For example, the SuperDraco engine block shown below was manufactured with 3D printing (see this article for some more information).