A mapping between controls of the head unit of a vehicle and functions of a navigation service application running on a portable device is received. Subsequently, an indication that one of the controls has been actuated is received via a communication link between the portable device and the head unit. A function is selected from among the functions of the navigation service application in accordance with the received mapping and the received indication. The selected function of the navigation software application then is executed. In this manner, the navigation service application is safely and efficiently controlled via the head unit.