Axxess AXRC-GM3 Data Interface Chime Retention 
Chime Retention Interface with Built-In Speaker (AXRC-GM3) by Axxess¬ģ. Replacing the stereo in a late-model GM car has a down side: the seatbelt chime and the turn signal click are actually piped through the stereo and into the speakers. New stereo = no chime. This module uses a speaker built into the module to generate the chime sound.
Instruction Manual
Product Information Sheet