For the cargo cover, the plastic ends from the tension rod squeak on the interior paneling or rattle on the rod. Common corrections for this (other than just removing the rod) are to place felt or some kind of cushion with an adhesive back between the rod and the paneling for the squeak, and between the plastic cap and the aluminum rod on the end that compresses for the rattle. It has also been found that the sounds will go away in warm or hot weather, and be very apparent in cold weather.
There are also some reports of lesser rattles and squeaks from the interior panels against the metal of the car, and in some cases between panels that overlap. Some people take it back to the dealer for this, some just pop off the panel and use that 1/2 inch foam weather-strip tape to pad the panel where it contacts the metal or overlaps another panel.....this is actually what the dealer would do in most cases.