[john4444]

There are no audio specs in the superficial iDrive 7.0 manual. However, the 2020 Porsche Cayenne owners manual, downloadable through the Good To Know app in either Android or Apple, shows that Porsche are still using the same, obsolete DAC they have used for years that compresses all audio to 320kbps. BMW probably are using the same or worse, obsolete DAC.

The old solution to bypass the poor quality DACs used by the entire auto industry was to plug an audio player into an analog aux input. A $30 audio player has a far superior DAC to a new BMW, Porsche, Mercedes or Lexus. Since there no longer is mass market demand for aux inputs, the car manufacturers have deleted them to save money. Now there is no solution to avoid forced audio compression. You can play through B&W, Burmester, Mark Levinson, et al., but only with a degraded source.