It turns out that it is harder to find a clunk-in-the-trunk, when the culprit is hiding under the hood
Attached is a photo of the top of the right front strut/shock absorber with the telltale orangey powder of the disintegrated upper guide support and 2 closeups taken with a WiFi inspection camera.
A pair of Bilstein B4 front struts/shocks, all the BMW orange bits and a spring compressor, are due next week. While I have the front end up on stands, I’ll replace the front brake pads with a set of Akebono EUR 1294 ceramic pads.
Funf Dreisig