Got the mach home and into the garage last night without the radio playing for once, and as I went up the riser that keeps water from blowing under the door there was a sound that came from the rear end. It sounded like rubber squeeking. So I drove around a bit and found the only time I can get it to do it is by going over a hard bump or a quick rise and fall in the road. I cant duplicate the sound by pushing down in the trunk. I'm pretty sure its got to be in the suspension somewhere but dont know what to look at. Im gonna take it to a dealership and have them look at it since its still under warranty but would like to have an idea what it could be in case they try and blow alot of smoke. Any ideas or suggestions?