A vehicular exterior rearview mirror assembly includes a mirror head portion and a reflective element having a glass substrate and a mirror reflector coated at a surface of the glass substrate. The reflective element is configured to provide a rearward field of view of at least about 15 degrees relative to a side of the vehicle and provides a substantially undistorted reflected image as viewed by the vehicle driver. The glass substrate is formed utilizing a bending element having a free form curvature. The reflective element, when accommodated by the mirror head portion at the side of the vehicle and as viewed by the driver, includes an image plane that establishes an object plane. Coordinates of the image plane and of the object plane are determined, at least in part, by the mirror size and by the free form curvature of the bending element used to form the glass substrate.