My 660 has quite a creak to it. It's most noticable when you sit on it, or press down on the grab bar, so I'm thinking it could be in the rear, but it also makes the same noise but not quite as loud if you press down on the front bumper. It seems to kind of be coming from the middle of the quad, like maybe the upper shock link or something. It squeaks pretty badly if you even look at it wrong... I'm hoping you guys can give me help pinpointing it and getting it taken care of.