Incorrectly installed brakes that cause the anti-rattle clips to rub. Bent dust shield are the most common, I have seen.
A bad wheel bearing also when turning it sounds worst or straight driving
That sounds like the starter isn't hitting the flywheel like it suppose to!
Sounds like you need new brakes. When they get worn down they make a metal on metal sound.
metal, right? Sounds like metal, yes.
Sounds like you've got a bad driveshaft.
Sounds like the shock bushings are worn out are loose.
Sounds like it is a metal other than gold or silver. Might be gold or silver plate over a base metal. The gold or silver (if it was plated) could have worn down revealing the base metal, or you might just be having a reaction to whatever metal it is made of...usually will contain copper or nickel, which is why your finger is turning green.
Sounds like worn out shock absorbers.
If you have a front-wheel-drive car, the first thing I would check would be the Constant Velocity (CV) joints.
the metal wears down from the gear turning metal against metal
he sounds like metal hiting metal
Turning metal into gold.