This dream may symbolize a desire to reconnect with a lost loved one or a part of yourself that has been neglected. The act of dropping a mail could represent a message or communication that you have sent out into the world, possibly seeking closure or resolution. The slow drive back could suggest a reluctance to fully confront this issue. The appearance of your dead uncle, who may represent a significant figure from your past, could symbolize a longing for their presence or guidance. The torn trousers and mud-covered appearance could represent a sense of disconnection or decay in this relationship or aspect of yourself. The phone call could symbolize a need for communication or a desire to hear from this person. The act of making him smell the car to recognize it could suggest a need to prove your identity or worthiness to this person. The hind seat placement could symbolize a feeling of being left behind or not being fully included in this connection. Overall, this dream may be a reflection of your subconscious longing for a lost connection and a desire to reconcile and reconnect with it.