Originally Posted by FunfDreisig

This is the main symptom of a very common failure. The clunk is almost certainly the result of the failure of the orange cushions (aka Guide supports) on one or both of the front shock struts. You can check this by opening the hood and looking at the top of the struts for an orange powder.

FWIW I spent a lot of time diagnosing a similar clunk that I thought came from behind the driver. But eventually I looked under the hood and found the real culprit. Here are links to two threads with the gory details.

https://xoutpost.com/bmw-sav-forums/...unk-trunk.html

https://xoutpost.com/bmw-sav-forums/...build-diy.html

Funf Dreisig