Edwin David Bliss
...If they just shot, even in the ambush, not in the previous turn or round, I would use the -2 DRM.
The -2 DRM should apply here ( IMHO ) even if they shot in the last round / turn...
...yes apply -2 spotting ( the Stug fired in the previous round/turn )
[ "Niteplayer" : You are correct : for Turn (!) read Round. ]