Where is the noise coming from??? front or back??
If it is the front,,i'd be checking for broken impeller shaft on the water pump,,,also alternator bushings/bearings,,,
is the noise constant?
Try coasting the car in nuetral,,,see if the noise goes away,,that'll eliminate everything after the engine,,except the rear wheels.
Other than that,,,you havent given enough info to properly diagnose this problem.
*Funny bit* Have you looked behind your stang??
maybee a kid tied a bucket to the back,,,that would explain the bucket going downhill noise. LoL