Implement interactions of holograms segments/parts with Unity3D

Hi all!

I'm creating a simple a very simple app by following the tutorials.
I've created the hologram of a motorbike (by importing a unitypackage of a motorbike), which is made by several "segments/parts" (frame,wheels, tank, handlebars, headlights);
The only interaction that i can have with these parts with the Hololens on is to let them drop once "clicked" , but:
1) these parts will disappear under the floor, without hitting any surface "real" or created with unity ( they won't roll similarly to Origami Spheres https://developer.microsoft.com/en-us/windows/mixed-reality/holograms_101)
2) The parts can't be dragged, once performed the gesture they will just drop down.

I would like that:
1) Parts will stop on a surface(not necessarly the "real floor" , even a plane added in Unity3D)
2) Once dropped, or even when "clicked", the parts can be dragged and moved in order to be re-attached to the "main structure". For example, drag a wheel away and than replace it.

Thanks in advance