A mirror reflective element sub-assembly for a vehicular exterior rearview mirror assembly includes a mirror reflective element, a mirror back plate, and a blind zone indication module. The module includes a first portion disposed at an aperture through the back plate and an internal structure that has reflective surfaces and at least one aperture. A circuit board is disposed at a second portion of the housing such that at least one light emitting diode is disposed at a respective aperture of the internal structure. The reflective surfaces are configured so that light emitted by the light emitting diode is generally directed towards the side of the vehicle. The circuit board is disposed at the second portion such that electrically conductive terminals of the circuit board are disposed in a connector portion that is configured to connect to a connector of a wire harness of the exterior rearview mirror assembly.