Squeak In the back

My son's 2001 mustang is making a noise in the rear end and he's coming by this weekend to work on it. Anyways, from what I'm told it makes a metal to metal squeak when it goes over a bump, and it happens slightly more often when the car is breaking, but it I'm pretty sure that the breaks themselves aren't the problem because I've checked them recently. I don't know if it's the shocks or what because it doesn't happen on a regular enough basis for me to pin down where the noise is coming from and it doesn't make enough noise to pinpoint it while it's turned off sitting still. Suggestions would be appreciated.

My first thought is shocks.

Figured it out. The car is a GT and the V8 in 2001 came with a rear anti-sway bar stock. I had him spray some WD-40 on it and it quieted down. It's not a perfect fix, but it will give him some peace for a couple of days.

I have a 2003 mustang and had a squeak in the back and the Ford company thought it was my back bushings- they change them and still had squeak- several weeks later could hear squeak more when used brake. Took car back to Ford company and my emergency brake cable was loose.

It was definitely the anti-sway bar. There were a couple of bolts to tighten up and it hasn't been a problem since. Although there was a cable running through what I tightened and maybe that was the emergency break cable. Either way though it was as simple a fix as tightening a couple of bolts and sprayin some WD-40 on it. Thanks for the tip though, now that you say that I'm going to go check to see if that cable was the emergency break line.