Originally Posted by michaeldch
In my case, the pace of chirping was determined by engine speed, so increasing engine speed caused the pace to increase. I think its also possible that if one of the smaller pulleys (such as the alternator) is the one causing the squeak, the pace will sound faster, even given the same engine speed (because the pulley is turning faster).
In the video, my car is running at warm-idle speeds - ~600rpms IIRC.
Lastly, it seems silly that the dealer is replacing components of the accessory belt drive system apparently one at a time. My thinking is that wear in one component indicates the likelihood that a related part is faulty - this is why I chose to replace all the routine maintenance parts at the same time.
Update, dealer had my car a few days, they ordered a new A/C compressor that they are going to install next week.
On the bright side, I've gotten all new maint parts on my vehicle during the factory warranty, plus I've been able to save miles on my car with it at the dealer and test the new f30. Though I like my 335 much much more.