official vehicle; company car; government vehicle
Refers to a car or other vehicle used for official business, typically by a government office, company, or organization.
The city hall's official vehicle is parked in the parking lot.
I headed to the site in an official vehicle.
自家用車 is a privately owned car for personal use, contrasting with 公用車 which is for official or business use.
Compound of 公用 (こうよう, 'official business') + 車 (しゃ, 'vehicle').