Prevailing Torque Fasteners
WARNING: This page is about a different car, the 2004 Saturn Ion Red Line, 2004 Saturn Ion 3, 2004 Saturn Ion 2, and 2004 Saturn Ion 1. However, it is still accessible from the selected car via links, so may be relevant.
Prevailing torque fasteners create a thread interface between the fastener and the fastener counterpart in order to prevent the fastener from loosening.