What is the pillar called that is used for mounting the post for rear door locks?

The correct answer pertains to the structural terminology used in automotive design, specifically regarding the columns that define the vehicle’s passenger compartment. In this context, the pillar used for mounting the post for rear door locks is known as the C pillar.

The C pillar typically supports the rear section of the vehicle's roof and plays a critical role in the structural integrity of the vehicle, especially regarding side impacts. It also serves as an anchor point for components like rear door locks, contributing to the overall safety and functionality of the vehicle.

Understanding the designation of these pillars is essential in automotive appraisal practices, as each pillar affects the vehicle's design, safety ratings, and repair processes. The A pillar is located at the front, supporting the windshield; the B pillar is between the front and rear doors; the D pillar is found at the rear, often in larger vehicles like SUVs or vans, and relates to loading and structural aspects rather than door locks.