What is a car used for?
A car is used to help you travel between places.  It is useful to get you to where you need to go in a shorter amount of time as opposed to any other means of travel like walking.  If you need to be somewhere fast a car could potentially be your best option and also save you some time.  Ways to use a car could be for the following: driving your kids to school, going out to eat, or taking a trip.
Instruction: What is a car used for?
Context: 
Response: A car is used to help you travel between places.  It is useful to get you to where you need to go in a shorter amount of time as opposed to any other means of travel like walking.  If you need to be somewhere fast a car could potentially be your best option and also save you some time.  Ways to use a car could be for the following: driving your kids to school, going out to eat, or taking a trip.