In the UK, a hire car is the US equivalent of a rental car. The term "hired car" can be especially misleading for those in the US, where the term "hire" is generally only applied to the employment of people and the term "rent" is applied to the temporary custody of goods. To an American, "hired car" would imply that the car has been brought into the employment of an organisation as if it were a person, which would sound nonsensical.