Oleg,
That formation shot got me thinking. Are you able to model the sound of unsynchronised German engines? I remember my Grandmother telling me how they could always tell when German aircraft were approaching due to the distinctive uneven pulsating sound of their engines. I think this was because the Luftwaffe couldn't or deliberately didn't synchronise their engines like the RAF did.
Would be great to hear distinctions between the sounds of different aircraft but realise this can't be a priority in a sim where you spend most of the time in a noisy cockpit!
I found an interesting thread on the subject here
http://www.pprune.org/archive/index.php/t-135198.html
Thanks