Zimmerman Auto sells new and used cars. Its assets are as follows: $(1)$ the showroom building, a separate building used to service customer cars, and various parking lots, $(2)$ a nearby acre of land not currently used by the auto dealership, $(3)$ new and used cars and trucks for sale to customers, and $(4)$ a car that is used to provide rides to customers who prefer to wait at home while their cars are serviced. The assets that are classified as plant assets on the company's balance sheet include: