I was thinking it would add a bit more realism to the cargo loading operation if the cargo started on the ground beside the vehicle and gradually disappeared as it was being loaded. And the reverse for unloading - as each item of cargo is unloaded it would appear on the ground nearby. This would be especially good for vehicles where the cargo is hidden (aircraft etc.)
It should be easy to implement, I think. For the user, place a load of cargo on the ground beside your vehicle, call it something like GROUND!1 to GROUND!20, and link it all to the vehicle and the existing CARGO!x items. It would normally be invisible, only becoming visible during the loading/unloading process.
It might not be workable for boats, as the "ground" position is different at each port. And of course it would clash with automatic loaders at hubs, but we always have a choice whether to use those.
What do people think?