Hi Pior,

re:
> Is there any way/setting to make the selection of solid objects appear clearly in wireframe view, somehow ?

You should be able to see the edges flash when you click on it, but other than that no.

When you're working directly with the objects I would recommend to set the objects back to normal display mode so you can see the selection.

MoI is not really set up to work with solids in wireframe display only.

- Michael