The rubber bushing for the suspension spring has fallen off from age. The suspension spring now "slaps" itself, metal to metal, causing the noise.
Dave the Barbarian - 2004 Shake Rattle and Roll Over Bad Food 1-18 was released on: USA: 28 December 2004
Loose shock mount or bearing? Loose component in exhaust system? Also, check all your ball joints. Changing the anti roll bar links fixed my rattle.
The brackets that hold the brake pads in place are worn and are allowing the pads to rattle.
Sounds like the shock bushings are worn out are loose.
To cure brake rattle replace the caliper pins with new ones do both sides and be sure to lubricate the new pins with high temp silicon brake lube.
Yes, the 2004 Chevy Impala SS does have a governor chip that limits its top speed. This chip is factory installed and limits the speed to just over 100 mph.
Squeak in tires (when turning in particular) could mean low tire pressure, or bald tires.
possible missing anti rattle clip on brakes....had same concern on 02 front brakes
could be wheel covers loose if its light sounding rattle. If it sounds deeper it could be sway bar links. could be the metal gas filler tube that Chevy thought would be a good idea to run it across frame rail with no buffer.
Struts costs for a 2004 Chevy Impala depend on where they are being bought from. At local auto part store they can cost over $100 while online they can be bought for less than $75 a piece.
Check for anything that may have come loose under the vehicle. For example, check the heat shield on the exhaust system, like the converters, muffler, and exec.
If it is a cruching, squeeky kind of sound you most likely need your rear struts lubed. Minor and inexpensive.