To see a trunk in your dream represents old memories, ideals, hopes, and old emotions. It indicates issues and feelings that you have not dealt with.
To see the trunk of a car in your dream signifies the things that you are carrying around with you.
To see the trunk of a tree in your dream signifies your personality, your character, and your inner sense of well being. It is symbolic of your backbone and the things that hold you up. If the trunk is thick and large, then it denotes that you are a strong, rugged and durable person. If the trunk is thin and narrow, then it suggests that you are a highly sensitive person.