2008 4.8 E70 39,000 miles, Heard a whiring/rubbing/bad beraing sound coming from my engine compartment while the engine was idling. The sound would intensify has I increased the RPM's while the car was in park, leading me to believe it was something tied to the motor. Took it to the dealer and was told its probablly the AC's compresor. Just wanted to bring it to everyones attention just in case you have heard a weird sound from the engine compartment. I'm glad I caught it before my warranty is up next month.