There is a rubber bushing that holds the anti sway bar.. if that has slop you will get a terrible clunk. I know this first hand from driving a few miles with my sway bar unattached. Wow that was noisy!

If something was misalligned your sound could easily be there.

If deeper thump look toward the larger bushings : front side or back (sway bar). If higher click sound look at the small joints like sway bar link.

If sway bar link you can tightly wrap with electrical tape and the sound will go away.

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2011 E70 • N55 (me)
2012 E70 • N63 (wife)