They are like clocks because they are precise. Ticking forward.

 They are like Birds because they are screeching to a halt. Flowing across the city.

 They are like horses galloping through their country. Their skin soft to the touch.

 They hover across the dirt. The shifting metal is good: they enjoy their owners.

 But the bad cars are ready to rebel;

 To crash, to malfunction the precise, and halting their continuous movement.
 They are bad cars because they cannot hold their steering wheels, or guide themselves past each other.

  In their ignorance they ignore the men flooding with bags under their eyes.

 They are bad cars and they hate their brakes.