The example is outdated, the rest of the information are not. You can use the multidae in general to create new parts without having to edit the original .dae files of vehicles (Whic his a bad idea, always)
As soon I have some time, I will do. By the way, the example is still valid. It's only the 'Wheels' example that is outdated, as wheels are working in a different way now. They way you do the thing is the same.
