Noise from rear (2011 X3 35i, 15K miles)

Metal-to-metal, slightly muffled 'clink' sound. Another interpretation could be an 'oil can' metallic noise. Right rear, best I can tell.
To make sound:

• Residential road, abruptly change direction from straight to left (e.g. some amount of body roll/twist on chassis)
• Drive in parking lot, low speed, abruptly change direction from straight to left.
• Strike a bump with right rear wheel at low speed (e.g. in a parking lot).
• Does not seem to happen as easily at speeds above 15-ish (it is noticeable enough that road noise would not mask)
• Does not seem to happen over undulating roads where entire body moves up/down.
• Does not seem to happen when both wheels go over an irregularity (e.g. speed bump).

Started faintly 2 weeks ago. Noise seems to be more re-create-able as days pass.

I'm about to make a service appointment. Anyone else experience something like this?

Thank you

It was a bad bushing deep inside the back seat mechanism. Whoda thunk?

I'll be...it's the kind of thing I would notice. I never would have suspected a bushing on the seat.

No strange clanks from my new X3...yet.