Central office production order. Term used by
muscle car enthusiasts, specifically Chevy, to refer to a car purchased through the Central Office. The CO was mainly used for specialty orders, i.e. a fleet of custom-color cars. Dealers found a way to use this to their advantage and have high-power engines placed in cars, all while keeping them completely factory, as all COPO vehicles were produced at
the factory, or reflected this in the VIN (vehicle
identification number). The term has since fallen out of usage since custom orders are many times placed into third-party hands.