Hi I'm new to this forum but I hope someone can help me. I have a 20007 118i upgrade with rear parking sensors. I recently go it serviced and when the it was checked it registered that all the parking sensors are working but there is not sound? Also outlay speaker could not be found but the shop said that in some of the newer models the PDC sound comes through the stereo system? has anyone has this type of issue before is so any solutions?