Why Does A Fast Car Slows Down If It's Engine Is Switched Off?

A car requires force to move. We know that F = ma, where 'm' is the mass of the car and 'a' is the acceleration provided by the car. So when the engine stops the acceleration of the car is zero. When acceleration is zero the force is zero. Thus a car stops when the engine stops. But it won't stop suddenly because of the inertia of the motion of the car. It slowly comes to rest.