I suppose, but these hubcaps have big holes in them, so I'm not sure how something could get caught in there, move around a lot, and not come out. Furthermore, there is more reason to believe this is not a hubcap problem (and so this test would just be a waste): sometimes I've heard the sound when the car is not moving, but idling. When it happens while idling, there may be, though I'm not sure, a correlation with putting it into/out of gear, for example shifting to/from park. And it doesn't happen constantly when it's moving either, just episodically. When it occurs with the shifting it's only like I think 1, 2, maybe 3 clicks (but they sound just the same and have the same frequency.).