For the first time I became aware of something weird. While I was in my car (car off, just on battery power) setting the clock radio, the old-school quartz clock that comes in the Volvos made a "clicking" noise. It sounded kind of like the clear plastic cover jumped and was similar to what happens when you snap a plastic fork, but not quite as forceful. When I tapped the cover, it did it again, but I couldn't get it to make anymore noise. The sound is not coming from the mechanics of the clock but rather, I think, the housing. I'm guessing it has to do with temperature changes or movement from vibration, snapping back into place at rest. I've heard the sound before (I think I even remember hearing it back when my mom drove the car) but it never really registered as something within the car and as something potentially fixable. The sound isn't really an annoyance, and I'm not going to bother taking apart the whole clock unit to stop the noise (since it doesn't bother me), but I was wondering if anyone else has had similar experiences with their clocks.