The rattle is probably the shutter button rattling in the housing. Its a known problem. You can take the housing apart and place a piece of foam inside or place a rubber band around the outside over top of the shutter button. No more rattle. I had the same problem with my go pro.
nice top to bottom run,but at 1min 56sec. those to dudes standing on the track,don't even look,good thing your a pro,he almost took you out,sorry jill i just had to say something,there's no parking on the dance floor,good luck at the world cups,your looking fast.