Bob I had the same thought a few months back-long story short one of the support beams had been slightly bent upwards by a mountain posing as a speedbump. The dealer was able to add another spacer and bend the bar back, now there are no issues. The rattle on cold start was beyond maddening, I feel your pain.
E88 N54 Alpinweiss/Coral Red/Motiv HTA 3586r Tial .82AR/Other stuff...652WHP
F30 N55 XDrive EBII