Thanks for reply, I was also inform by my dealer that the SOS(teleaid) could be utilized as a vehicle locator system, but must be activated. I did recently install a multimedia audio system and would like to be able to protect it with shock or glass mic sensors. I know of somebody who has a E320,left it overnight @ airport parking and someone JACKED UP his audio system at the same time they destroyed his dashboard...seeing it got me itching for an UPGRADE.