Lately my S has been making this strange creaking noise from the back of the car. When I roll my windows down, you can hear it loud and clear. It happens whenever I come out of 1st gear, or reverse. It also happens when I tap on the gas lightly in first gear (so as to make the car jolt a little). So, I can

 

Try the ole' relube retorque of the spindle nuts. Also check the diff fluid and the state of the rear axles. All of these can effect such things.

 

Well, my mechanic said that the dealer confirms that there is a TSB out for this problem. It has something to do with the axle. The cost to fix it is ~$130. My car is no longer under warranty and add to that that my car is already at the shop, I