company car
A car owned or provided by a company for business use.
The sales department purchased a new company car.
I head to the client's office in the company car.
公用車 is a government or public office vehicle, whereas 社用車 is specifically a company car.
社用車 is a car owned and used by a company, the standard contrast to マイカー, which is a personal, privately owned car.
Compound of 社用 (company use) and 車 (car).