[Chauncey.Bishop]

Rattles usually happen on the lower frequencies but since your problem is with the higher frequencies, I'd suggest trying the same track from a different source. Often times people who stream bluetooth forget that their source has an equalizer setting on it, causing the system to operate within frequencies it's not built for. Once you've eliminated that easy solution, I'd try listening to the same track on repeat until I can finally get the equalizer settings to where it stops rattling. I know it's a painful process but you searched for a car with the B&O so may as well put in a little effort now for a lifetime of pleasurable listening.