THE REAR COLLISION ALERT SYSTEM HAS A DESIGN FLAW. THE SOUND ADJUSTED BY TECHNICIAN TO 100% IS BARELY AUDIBLE BY THE DRIVER, AND TYPICALLY AT OR AFTER IMPACT. IT IS ALSO NOT LINKED TO THE CAR DASH SOUND SYSTEM, SO THE RADIIO DOES NOT SHUT OFF ITS VOLUME. IN THIS INSTANCE, THE AUDIBLE ALARM IS INAUDIBLE. I HAVE HAD TWO ACCIDENTS WITH THE VEHICLE WHILE IT IS IN MOTION. THE DEALER DOES NOT ARGUE WITH MY ASSESSMENT, BUT SAYS THE SYSTEM IS FUNCTIONING AS DESIGNED. ATTACHED IS MY MERCEDES SERVICE RECORD DATED 10-23-2018 EXPECTING THE PROBLEM TO BE CORRECTED BY DEALER PROGRAMABLE TECHNOLOGY. I ADVISED THE SERVICE MANAGER THAT HE MIGHT WANT TO DISCUSS THIS WITH MERCEDES BEFORE I FILED THIS REPORT. HE DECLINED. THIS IS NOT A SAFE CONDITION AND COULD RESULT IN SERIOUS INJURY OR DAMAGE.