B or D, they both had no siren. The sirens were used only early on to strike fear in the populations they were bombing. This later was one of the points brought up in the war crimes trials after the war.
However, during the war even the B models removed it after those early stages of the war. You'll find most pictures of Bs are missing this very obvious and visible item.
It would be a giant propellor blade over the rounded fairing in front of the middle guy's elbow here:
![](http://www.warbirdsresourcegroup.org/LRG/images/ju87b-1.jpg)
No siren.
Also no siren.
![](http://www.asisbiz.com/il2/Ju-87B-Stuka/Ju-87B-SG1/images/1-Ju-87B-Stuka-SG1-(6G+-)-+G50-65.jpg)
Even the fairing is gone on this one (and many others).
![](http://www.wwiivehicles.com/germany/aircraft/dive-bomber/junkers-ju-87-stuka-dive-bomber/junkers-ju-87-b-stuka-dive-bomber/junkers-ju-87-b-stuka-dive-bomber-02.png)
Another with no siren.
In fact, actually finding photographic evidence that this siren was ever used is RARE. That is why AH does not have it modeled, aside from the B/D differences. Either model would not have it.