 These windows were usually non-functional; however, in the case of the AMC Matador coupe NASCAR racers, the small windows that came with the Barcelona II trim package actually helped to clean up the aerodynamics when such windows were open to the wind under racing conditions.In some cars, an additional feature was the so-called opera light that was mounted on the outside of the B-pillar or C-pillar and illuminated when the exterior lights were switched on.Opera windows had fallen out of vogue by the mid-1980s, as changing automotive styles moved away from the upright notchback.