I am exhausted and feel a bit ill as I've been travelling on buses on an empty stomach etc.
Your dream could have been prophetic as your XW did get a flat tire, however, cars in dreams also represent a person's life journey and if you were flattening the tire it could be that you are trying to stop her from going down the life path she is currently going down.
Jo.
PS: I know how exhausted you are, jdd. Keep your chin up. I am thinking of you.