Well, sitting yesterday in a 109 I got badly surprised. So no longer sound radar here.

Sitting before yesterday in a spit (with closed cockpit) I could hear the 109 that overshot me ...

Where is the report in the bugtracker (for voting on it) or is it to be created?

I don't want to hear any external sounds with my engine running whether with open or closed cockpit. Should be not too difficult to implement. They have already successfully implemented a difference in sounds when opening or closing canopy (wind sound or no wind sound). So they just need to add an if clause checking for engine running or not.