I had a squeak in the back passenger side as well. I searched for quite some time for that noise. (I thought something was in my trunk to cause it) ha ha. My springs were the cause. The spring on the passenger side was broken in 5 different places, and my driver side was broken but not as bad. The Ford dealership that I went to said that was a common problem for the Contour. So, check the springs. I also changed out the struts, just to be safe, especially since I didn't want to bring it back a 2nd time for repair.