Their hands glued to the windshield, they feel the vibrations and smile. The sound of the subwoofer is powerful. The faces are focused. The sound of the bass increases, they stick to the body, the sheet vibrates. Ken opens the trunk and looks at the subwoofer built into the cabinet. The others join him. The demonstration is in full swing, sound and vibrations are the central point of this gathering where we cross paths with car audio enthusiasts whose love of low-frequency sound and bodywork are a daily passion.