What could this be?

Based on a few things, I am led to believe that one of my rear wheel bearings are bad. I am constantly hearing a metallic (almost bean in a can) sound, as well as a wobbling noise that I can hear especially well at lower speeds. Are these the signs of a bad wheel bearing?

The noise is only there when I'm moving, the car drives fine (Stevan drove it right after I bought it and said everything seemed fine). And as far as I can tell, nothing is slipping.

Also, the wobbling might not be related to the rattling, could be a bad wheel bearing on top of someone else. I might take it to Stevan again for an evaluation. I even went underneath the back end and tightened everything up, the only thing that was slightly loose was the drivers side sway bar end link.

Brake pads in the rear loose?

That could be a possibility, I am replacing my brakes soon anyways but is there a quick way to check? Also, that wouldn't be related to the wobbling noise right?

If the rotor is out of round. Have you ever felt a pulsing on the brake pedal as you slowly came to a stop with light pedal pressure?

I'm new to the "guess this sound on a Miata" game though...

No real pulsing that I can tell, my pedal is sort of soft though, even though I bled my brakes not too long ago but I know my brakes are in pretty bad shape.

Did you bend the dust shield? Could be the dust shield rubbing on the rotor.

When I lost a rear bearing it was more of a deep roar.

Do you have any play in the hub??

I don't think any of the dust shields are bent but I'll check it out. I'll also see if there's any play.

I've had a noise similar to what you described and it ended up being a bad tire. Didn't figure this out until after I replaced both rear wheel bearings.

Hmm, seems weird since my tires are in good shape with no uneven wear. Were your tires worn in a weird way?

Nope. Try rotating the tires and see if the noise moves.

I'll have to do that. I think my tires are directional but I'll go back to front to see if anything changes.

Also now that I've done a little research, it seems like the rattling could be an exhaust heat shield? Man, I really wish I could put this car on a lift and inspect everything. I'll have to grab a set of jack stands sometime soon and look at things.