
Retrieved 26 November 2022 – via Google Books. The Cars of American Motors: An Illustrated History. Archived from the original on 26 October 2009. "What's a Matador? The AMC Matador, Rebel, and Classic".

SMALL PORTHOLE WINDOWS WINDOWS
These windows were usually non-functional however, in the case of the AMC Matador coupe NASCAR racers, the standard roll-down quarter windows were causing aerodynamic drag. In an age of decreasing dimensions and increasingly common use of non-opening rear side windows on 2-door models, a variety of shapes of rear windows may have helped passengers there to feel somewhat less claustrophobic. The windows were intended to offset the significant blind spots created by wide C-pillars that were characteristic of many American cars produced at this time. 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. Standard on all the coupes was a fixed triangular rear quarter window while higher trim versions used a rectangular vertical opera window. General Motors introduced an all-new line of mid-sized "Colonade" models for the 1973 model year. Most often, opera window variants were applied on two-door hardtop or coupé models, spanning all types of vehicles from economy compacts to flagship personal luxury cars, in which latter exploding realm they became "recognition elements" seeking to add a vintage element to their styling. Almost all personal luxury cars would adopt opera windows, usually framed by a vinyl roof. Opera windows began reappearing in the early 1970s in such vehicles as the 1972 Continental Mark IV. "The hottest thing going was the 'porthole' window in the rear side pillar – called 'opera windows' – that came in during the horse and buggy ". It was provided as an option to improve rear-quarter visibility with the removable hardtop in place. Perhaps the most notable return was the "porthole" in the 1956–1957 Ford Thunderbird. Opera windows saw their demise in the 1930s. and even a fabric top in the style of a brougham with oval opera windows framed by landau bars". For example, "the Elcar in 1924 was good looking .

The design element of a distinct, fixed, centered opera window was borrowed from such windows in horse-drawn carriages and used during the classical era of automobile styling. 1991 Cadillac Brougham opera window as part of the rear door
