Objects on Wings are called 'Panzerfaust' hand launched tank grenade rockets, able to take out large Tanks. They had a unique design for a cone shell casing that caused massive damage to Tank hulls.
The Bucker Bestmann, near the end of the war, was rigged with 4 Panzerfaust rocket units, controlled electrically from within the cabin, making it an armed aircraft capable of taking out a tank, if it could get close enough. The accuracy with Panzerfausts at long distance was guite dismal, requiring a pilot to get very close, which in a small plane as this, would be deadly as they would probably be shot down sooner then they could get a site aquired.
The Bestmann was the trainer of Luftwaffe aces and a couriour aircraft at most. No more....
PS: Also used by the Swedish airforce as a trainer as well, as they were built in Sweden, Germany, and Yugoslavia. (Popular little plane back then.. also used for air racing after the war).
Bill