A rotary control knob for an automobile has a central portion comprising a display and a radial encoder disposed therearound. The display selectively displays first information regarding a first function of the automobile and second information regarding a second function of the automobile. The radial encoder selectively receives input regarding the first and the second functions. The radial encoder can selectively receive input regarding the first function only when the first information is displayed on the display, and receive input regarding the second function only when the second information is displayed on the display. Or, the radial encoder can selectively receive input regarding the first function only when the first information is displayed in a primary area of the display, while displaying the second information in a secondary area. Capacitive coupling can identify user seat location to provide driver and front passenger specific zone features.