This thread triggered a memory in my head of something that I read about - so I looked it u. Found reference ( but no pics unfortunately) in " Land Power; A Modern Illustrated Military History" . I found mention of 88mm Flak-37 and Flak 41 respectively in the above book on page349, headed "Flakpanzer".
Apparently they were two experimental types on the "grille" prototype "Waffentrager" chassis They featured the 88mm flak 37 and Flak 41 respectively in a mount with folding shields rather like the Mobelwagen. There were apparently no production plans for these costly and heavy vehicles, however, and they appear to have been made by Krupp, solely to make use of the available chassis - which otherwise would have remained unused.
Hope this helps. johnnybach