I think that the best practice is to create two distinct families:
a "Detail Item" family including the 2D geometry of wheelchair.
an "Entourage" family and host the 2D "Detail Item" family in the plan view.
You will use each family according to your needs while keeping the consistency of the plan representation:
1. use the "Detail item" when a 2D representation of the wheelchair has to appear on blown-up part of the plan (a callout, for instance) but you do not want the wheelchair to appear in other views of the same level. The "detail item" will only appear in that specific "blown view" because is view hosted.
2. On the other hand, if the wheelchair has to appear in all views of your project you can use the "entourage" family (that will actually use the same 2D hosted "detail item" for the plan view). The "entourage" family is workplane/level hosted so it will appear in all plans views where the wheelchair is visible.
Furthermore, you could create 3 more "detail item" families in order to have the representations of the front, back and side 2D views that can also be added to the entourage family in order for the wheelchair of the entourage family to be visible in frontal views.
hope it helps
Aghis