Since the map is also useful for battle of France scenarios, maybe we could have optional sirens once the new sound engine is done.
Imagine this:
1) Go to the loadout screen, the part where you choose what guns and bombs to load on the aircraft. For the Ju87 there is a siren option.
2) Enabling the siren gives the characteristic sound during dives but negatively affects the FM, disabling sirens gets rid of the sounds and gives you some extra speed (just like subtracting guns currently affects the aircraft's weight and handling).
3) Depending on player preference or the mission/server settings (eg, BoB or BoF scenarios), it's possible to have any of the two configurations.