Suspension noise
 

My first thought is to check your rear upper control arm. The bushings might be too old or it's hitting the car as you go over bumps.
If it is I'd get the ROUSH one. It's built better then the OEM one. And no you don't need an adjustable one. ;)

This :agree: If it's not the sway bar end link bushings? Then I would definitely suspect the upper control arm bushing... Also agree that an adjustable is not necessary and would also recommend the Roush as well :nice:

Don't you have a regular trusted shop or mechanic near you?? Unless you have a rare trusted dealership near you, most dealerships will find something. it's like going to a doctor for a check-up. They WILL find something. Not always to your benefit. Good luck!!

Here's an update, took it to the dealer and found that my axle is hitting the exhaust pipe.. I saw the scrape marks on the pipe so now I have to find an exhaust shop to bend it. There's also another noise I hear that sounds like a knocking sound but isn't coming from the engine, I hear it upon start up at times too. Could the flywheel cover be loose making it rattle??

Sure know that feeling quite well... Went through the same experience with exhaust pipes hitting the rear axle... Only way I could stop it was by rotating the over the axle pipes along with readjusting the axle-back mufflers... it's even more of PITA after the suspension has been lowered, as it reduces adjustment/clearance space :banghead:

I bought my new Mustang GT at an auction, using a vehicle inspection report and unusual noise from the rear was my first and for now only one problem. I had the sway bar mounts replaced and it worked out.

No offense, but I'd hardly consider buying a Mustang GT at an auction as being new... Perhaps "new to you" is what you intended to post lol. :jester: All j/k aside, glad to know that replacing the sway bar mounts resolved your rear suspension noise issues...