RE prototyping, it's hit or miss if they have it internally. It's more likely they have a CNC or two to facilitate that, for prototypes it's as good or even better. If you need something printed, you go external as it doesn't make sense to have a printer in house, if it's not used more or less 24/7 - there's maintenance, buying the materials and then there's personnel you need to run the machine, who needs to be up to date with new developments, etc. On the other hand there are loads of companies around the world offering 3D printing...