Recently my 2013 XC70 3.2 has exhibited and sound like the door opening in an old horror movie. It seems to come from under the drivers seat. It only happens when I am going over a slightly raised area in the road and only noticeable at slow speeds, like when the car rocks a little. It does not seem to be in the suspension. I notice when I position the seat a bit forward, closer to the steering wheel and lowered all the way the noise is almost gone! I have checked for anything under the seat and it is clear, except for the seat mechanicals. There is nothing between the seat and the center console. Any ideas?