Noun
C-pillar (plural C-pillars)
(automotive) The vertical support dividing a car's rear window from its rear windscreen, or, if the car has an additional window and D-pillar, the support dividing the central and rear windows.Column arrangement in cars
English Wikipedia has an article on:Pillar (car)Wikipedia
Key signature design elements such as the 'tiger-nose' main front grille, the distinctive C-pillar and the straight lines and smooth surfaces ensure that Stonic is instantly recognisable as a Kia. Source: Internet
It’ll be worth it alone to get rid of the CT5's unfortunately black triangle panel on the C-pillar, at least. Source: Internet