I see there was firmware updates in the past that broke the front sensors but for me, for quite some time now, my rear parking sensors will not work...but only occasionally. And when it refuses to work, it just won't work period. See the video here: Neither the chimes nor the proximity alerts show on screen. I can go back and forward all day long and it just won't work when it stops working. Has anyone seen this? I have been to the SC before for it and they just tell me they can't reproduce it.