Quarter glass

[3] Many early closed cars, such as the 1933 Pontiac Economy Eight had front and rear vent windows called "ventiplanes" and were installed on all GM products that year.

1933 was the first year all GM vehicles were installed with optional vent windows which were initially called "No Draft Individually Controlled Ventilation" later renamed "Ventiplanes" which the patent application was filed on 28 Nov. 1932.

[8] This may be a side window between the B-pillar and the C-pillar, and in the case of US minivans between the C and D-pillars (examples include the Chrysler Town and Country power-operated venting glass).

[9] A quarter glass can be found set in the body or A-pillar ahead of the front door opening (examples include the Buick Encore, Chevrolet Lumina APV, Toyota Prius, Opel Astra J, Mitsubishi Endeavor, Fiat Grande Punto, Suzuki SX4 sedan, and the 8th-generation Honda Civic sedan).

The fixed portion of the glass is separated from the main window that rolls down by a slim opaque vertical bar (see top left image of a close-up of rear door).