Hey, I was looking at a car and the dealer told me the battery is at the back in the trunk. When he opened the hood he showed me how I would jump it if needed or anything else. He said there is one rod (that was visible coming through a connection from the battery) for the positive and for the ground I would just connect to any metal surface on the car. Thinking about this can someone explain why the ground can be connected to any metal surface on the car?????? I know the ground is just a reference point but is the ground of the battery connected to the metal surface of the car too? How does this make sense.. Thanks!