The term 'Parking Space Filler' refers to an AUTO, which is a four-letter word. An AUTO is a vehicle, usually powered by an internal combustion engine, used for transportation. It is typically a car or truck, but can also refer to other types of vehicles such as vans, buses, and motorcycles. Parking Space Fillers are typically used to fill up empty parking spaces in order to maximize the use of available space. They are often used in busy areas where parking is limited and can be used to prevent illegal parking.