A vehicular exterior sideview mirror assembly includes a main mirror element having a first primary field of view rearward of the vehicle and an auxiliary curved mirror element having a second auxiliary field of view rearward of the vehicle. The main mirror element and the auxiliary mirror element are adjacently disposed at a mirror backing plate element in a side-by-side relationship. The first primary field of view of the main mirror element may overlap the second auxiliary field of view of the auxiliary mirror element by between about 2 degrees and about 20 degrees. When used in an exterior sideview mirror assembly of a vehicle, the main mirror element may have a rearward field of view that subtends an angle of less than about 20 degrees relative to the side of the vehicle.