1. A navigational mirror system for a vehicle, said navigational mirror system comprising: an interior electrochromic rearview mirror assembly mountable at an interior portion of a vehicle, said interior rearview mirror assembly comprising a reflective element, said reflective element having a front portion that faces generally toward a driver of the vehicle when said interior rearview mirror assembly is mounted in the vehicle, and having a rear portion that is generally opposite said front portion; said reflective element comprising a transflective mirror reflector, said reflective element being at least about 15 percent transmitting to visible light incident at said rear portion of said reflective element, and at least about 60 percent reflective to visible light incident at said front portion of said reflective element; a video display disposed to the rear of said rear portion of said reflective element, said video display emitting light when actuated that passes through said reflective element to be visible to a driver of the vehicle viewing said front portion of said reflective element; a user input from a driver of the vehicle when the vehicle is at an initial geographic location, said user input comprising a destination address; said video display displaying driving instructions, said driving instructions providing instructions to said destination address, said driving instructions being viewable by a person viewing said front portion of said reflective element; wherein a particular instruction of said driving instructions is displayed when it is appropriate to display the particular instruction to the driver of the vehicle by actuating said video display disposed behind said reflective element and wherein actuation of said video display ceases once the driver successfully completes the particular instruction displayed; wherein said video display is back lit by at least one of (i) a cold cathode vacuum fluorescent light source and (ii) at least one light emitting diode; and wherein said video display is operable to exhibit a display intensity as viewed by the driver of at least about 200 candelas per square meter when said interior electrochromic rearview mirror assembly is mounted, operated and viewed in the vehicle.