As a rule, metallic-sounding rattles are generally more irritation and less safety-related issues, but you never want to ignore them. The people at tire and alignment shops are experts at finding the causes of noises and vibrations, and they often perform the inspections for free if you have the repairs done there. I can help if you want to do the inspections yourself.
The more common causes of these types of noises are worn or broken anti-sway bar links, and loose front disc brake pads. Broken or rusted anti-rattle clips on brake pads cause this too. Loose pads will stop rattling any time you apply the brakes, even lightly. Broken anti-sway bar links can sound like a tambourine when you drive over bumps, but the style used on your car causes more of a very light, barely perceptible thumping-type of rattle that is only heard at lower speeds. You will rarely hear them at highway speeds. To identify worn links of this style, drive slowly through a parking lot, then observe the noise stops whenever you turn slightly in either direction.
The safety-related items include ball joints and tie rod ends. These also do not cause metallic-sounding rattles. You will hear more of a single clunk or a few clunks in a row when driving over bumps. A real badly-worn tie rod end will cause the car to steer slightly to one side when you accelerate, and go the other way when you slow down. If ball joints or tie rod ends are ignored long enough, one can separate leading to loss of control and a crash. Most of them give you plenty of warning noises long before that happens.
Also consider worn control arm bushings, worn struts, and worn upper strut mounts. These can cause that wheel to not stay in proper alignment as you drive, so besides dull thumping noises, you can see bad tire wear patterns, excessive steering wander, and less-than-ideal handling. Even loose exhaust heat shields will cause metallic rattling noises.
You might find more information in this article:
Wednesday, December 5th, 2018 AT 6:02 PM