Saturn chose thermal plastic exterior body panels for their strategic advantage. Unique to this technology is the need to manage thermal expansion.

Thermal expansion allows exterior panels, e.g. fender, door, quarter, to grow and contract with changes in temperature. The method in which the exterior body controls and directs this expansion is through a carefully engineered fastener system and exterior panel design. This panel design consists of a series of net and slotted holes to direct this growth. The growth is directed forward for the fender and rearward for the quarter panels. The growth of the doors on the SL1, SL2, SW1 and SW2 is forward for the front door and rearward for the rear door. The growth of the SC door is forward. However, the growth of the rear access door is rearward.

To allow this system to function, the fastener design consists of a steel shoulder bolt and plastic spring washer. This system allows for adequate compression of the joint for panel positioning and retention, yet allows the panel to slide along the slot for thermal growth.

To maintain functionality of this engineered growth management system, you MUST