A mirror reflective element sub-assembly includes a mirror reflective element, a mirror back plate and a blind spot indicator. The mirror back plate has a generally planar portion and an indicator mounting portion. The indicator mounting portion of the mirror back plate is angled relative to the generally planar portion, and an aperture is established through the mirror back plate generally at the indicator mounting portion. A heater pad is disposed at the rear of the mirror reflective element, and a light transmitting portion of the heater pad is generally aligned with the aperture of the mirror back plate. With the light source of the blind spot indicator activated, light emitted by the light source transmits through an indicia element, the aperture and the light transmitting portion and exits the mirror reflective element at an angle relative to the generally planar portion of the mirror back plate.