My 2.5 non-Sport #1117 makes two "bong" noises (I think maybe they call it chimes) when I turn it off, but only some of the time. I cannot figure out what circumstances cause it to happen. As a side note, I dislike how loud the chimes are. There's one when I start the car, and a really annoying pattern of them when the NAV finds the satellites. But the ones when I turn the car off don't follow any pattern than I can discern. I'll be someone here can tell me what it means. Thanks in advance.