A mirror reflective element for an exterior rearview mirror assembly of a vehicle includes a mirror substrate having a front surface and a rear surface. The mirror substrate has a first reflector portion and a second reflector portion, with the first reflector portion having a principal reflector portion of the mirror reflective element. The rear surface of the mirror substrate has a curved recess established thereat, and the second curved reflector portion is established at the curved recess. The curved recess has a radius of curvature that is less than a radius of curvature of the first reflector portion, whereby the curved recess, when coated by a reflector coating, provides a wide angle auxiliary reflector portion integrally formed with the mirror reflective element.