Let me drive into warehouse even if max vehicles are assigned

Situation: I own a warehouse that already has the max number of vehicles assigned.

I am bringing 16 new pallet shelves to the warehouse in a spare van. Currently, I either have to park outside and bring them in one handtruck at a time, unload, go back out, etc. Or I have to unassign the current vehicle, drive in my van, unload, hope I didn’t miss a delivery, then drive the correct vehicle back in.

This seems silly as the warehouse is plenty big enough for my spare van to pull in without getting in the way of the vehicle slot and would make things much more convenient for upgrading my warehouse.