HTC,
If you have time to fiddle with this minutia...
wind sound audible at all speeds (just softer at low speed) and volume adjusted by Calibrated Air Speed instead of True Air Speed.
turret sounds for buffs.
bomb bay sound for buffs.
belly landing sound for gear up landing/ditches.
ground roll sound for standard takeoff and landings.
those are the only glaring sounds missing in the game for the most part.