Free Vibration
WARNING: This page does not describe the selected car, but rather 58 other vehicles, including the 2003 Saturn Vue, 2003 Saturn L300, 2003 Saturn Ion 3, 2003 Saturn Ion 2, and 2003 Saturn Ion 1. However, it is still accessible from the selected car via links, so may be relevant.
Free vibration is the continued vibration in the absence of any outside force. In the yardstick example, the yardstick continued to vibrate even after the end was released.