Introduction to the A-Pillar An A-pillar is a name applied by car stylists and enthusiasts to the shaft of material that supports the windshield (windscreen) on either of the windshield frame sides. By denoting this structural member as the A-pillar, and each successive vertical support in the greenhouse after a successive letter in the alphabet (B-pillar, C-pillar etc.), this naming scheme allows those interested in car design to have points of reference when discussing design elements. Source: http://en.wikipedia.org/wiki/Pillar_(car)
Graphic shows common pillars in sedan, coupe and wagon (or SUV car formats
A-Pillars The A-pillar along with the C-pillar are the most stylistically interesting for car fans. The A-pillar is in many ways the equivalent of the a human neck line, where the face for the car flows in to the body. The other notable aspect of the A-pillar is how it is integrated with the lines of the hood.
B-Pillars The B-pillar play a key role providing strength to the midsection of the vehicle. Many sportier cars tend to not have a B-pillar present. The E class family from Mercedes (opposite) shows how the placement and treatment of the B-pillar has remained unchanged through seven generations.
C-Pillars The C-pillar is often the most heavily leveraged pillar from a styling perspective. BMW has made the C-pillar their own with their distinctive curved C-pillar called the Hoffmeister kick that appears in some format in all of their cars. Coupes also rely heavily on the C-pillar to create streamlines shapes. One of the most iconic is from the Ford Mustang.
D-Pillars D-pillar really is the end of the line, in many ways this pillar is designed for the necessity to house the rear door in a wagon or SUV.
How many Pillars? The VW Bus is a great example of perhaps one too many pillars almost as many as the ABC...