These items are linked across other things that are in that same category, but they are not linked to stashes of a different category. I.E. different cars will share the same stash, but they will not share stashes with motorcycles and apartments.
Ha, stashes, that's what I meant.
But it makes no sense in my eyes to have different category of stashes.
Especially since the stashes has no limit.
For example, my inventory is full. I then go to my bike, throw my items into it and they end up in the stash of my apartment.