To facilitate the design and validation of comfortable automotive seats, it is necessary to thoroughly understand how the occupant-seat interface affects the perception of comfort. Previous studies indicated that the local supporting properties of the seat back, namely the regional compliance and regional stiffness, play a significant role in the perception of seat comfort. The purpose of this study was to investigate the effects of these properties on perceived comfort. The study used five production seats as test samples. The regional force-deflection properties of the seats were tested, and eighteen participates subjectively evaluated the seats for the perception of seat back compliance and stiffness. The quantitative and subjective test data was used to examine the relationships between the local supporting properties of the seat back and the perception of seat comfort. Based on the testing procedures, recommendations for regional stiffness and lumbar prominence were made.