I can have packages sent from all over the country and they make great time across the distances until they get to my local post office. Then they stall out. As in lingering in my local post office for a week. Delivery tracking gets marked "DELAYED IN SHIPMENT." It is not a delay in shipment, it is a delay in final delivery. You know it's there at the post offce, and you can't even go pick it up because they then claim that the package is out on the truck for delivery. Ridiculous...
Probably because Mercedes makes a very reliable and widely used delivery vehicle. Few want to play in that space.