Had a refreshed six seat MX for about a month now, and I usually have two car seats in the middle row. Lately I have been driving without the car seats, and I notice when driving there is a creaking/clicking sound coming from what I think is the middle row. The sound goes away when there are car seats attached, or if someone is sitting in the middle row. Anyone know what the noise can be? I was thinking about taking it to a SC, but I know if I can't pin point the source of the noise they won't do anything.