Holding your car key fob against your head can indeed extend its range. This phenomenon occurs because the human body, rich in water and electrolytes, can act as a conductor and enhance the transmission of radio waves emitted by the fob. When you press the fob against your head, your body effectively becomes part of the antenna system, boosting the signal's reach.

This method leverages the body's conductive properties to amplify the signal, allowing the car to receive the command from a greater distance. It's a simple trick that utilizes the body's natural composition to enhance the functionality of your key fob.