Generally all people in a dream represent you. The father in a dream signifies what you were taught in terms of aggression and asserting yourself to become independent, whether you are a man or woman. The father portrays that part undergoing exploration, and the dream offers a message about its well being through the drama of what takes place with the father.
Dad will appear in your dreams when you are exploring the influences that he holds over you. If he is driving the car - the dream can be showing how his influences are currently driving you. When he appears in your dream - examine his presence as your own judgements that can be either positive or negative. Similar to police appearing in a dream - dad can represent your critical tapes. Since everything in the dream is representing the dreamer - it is not 'dad' that is the focus - but the aspects that you adopted from him.