Consider this question on a programming site (the question relates to renderers, ignore that).
Selecting an unseen "back" part on a 3D object has wide application.
i) When the user selects a "back" object, what is the best way to then show the whole object ... transparent, with only the selected object solid? (roughly as seen in the example there) wireframe? Something else? Many questions arise such as ... should you during that state reduce the whole object to only an overall outline (whether transparent/whatever) or indeed still show each part (again whether transparent/whatever), if highlighted how so, etc.
ii) How would you select by pointer "through" an object, consider the case there might be not only one but a few parts "in the line of" your pointer position through the 3D object.
Indeed, have any standards emerged for this unknown to me? Do any whacky ideas come to mind: perhaps a "mirror" behind, or some sort of spatially cueing object comes in to play.
This could have particular application when using 3D mouse or virtual gloves - it would become a very common problem, how to show a 3D object when you reach "through" to a part which is not visible from the current normally-rendered view.