This might be the best topic ever!
In my believe the mighty RR is self curring: I’ve had noises at several occasions and after some time they went, it reminds me as if its human. Perhaps it ( RR ) has had a bad day.
Driving in France last Summer, suddenly something started shirping like Hell and if you just past some cars at high speed and you don’t like to stop and open the hood; so I turned up the audio, wich offcourse did not kill the noise but after3 minutes the shirping was gone! Bring out the champagne! It never made that noise again.
Also last summer suddenly there was white smoke coming out of the left air blower in the dash, this occasionaly repeated itself for some 3 weeks and after that it is gone!
In Scotland last September I crashed the right mirror into a van comming up from the other side in a to small road and the glass broke, it ( the RR) puked out its spasm on the doors on the right side and I had a lot of trouble to get it cleaned, so to speak as it ( RR) was angry because what I did to it . Offcourse to fix the broken glass it needed some help from myself and the BMW dealer network who could sell me this mirror glass at 150 euro only.
When I was young, seeing car pictures or viewing cars on TV etc., what noise did we make: whroooommmmm, brommmmm, griiiuuummmm, whaamammmmmmm........
And then there was that back seat noise, that also curred itself during time!

hahaha