What is the ruling on working for an insurance company where we only insure company cars?

The ruling on working in insurance depends on its type. If it is cooperative and solidarity-based (takaful), then there is no harm in it, whether it pertains to car insurance or anything else. However, if it is commercial, based on gharar (excessive uncertainty) and gambling, then working in it is impermissible, due to the Almighty's saying: "And do not cooperate in sin and aggression" (Al-Ma'idah:2). There is no difference whether it pertains to car insurance or anything else; all of it is forbidden.