Who owned the car or what they did with it is irrelevant. What you want to know is how the car was ordered and by whom. That can only come from factory documents like a window sticker, invoice or broadcast sheet.
If my dad is a small town constable that has to buy his own car and he goes to a dealer to buy a car and he buys a spring special dealer incentive discounted car to use on patrol and he outfits the car as such, he is using it for ‘cop car’ purpose but it was not ordered as a ‘cop car’.
How does this work out financially for the constable?
Do they pay enough per mile to cover the loan and maintenance plus an hourly wage or salary for police work performed?