An interesting photo as the Vomag Omnibus 7 was a civilian transport vehicle. There isn't a lot of information available about the Omnibus 7. The variant is known as the Vomag 88mm Flak 18 Waffentrager. It is an example of the need to get such an excellent but horribly immobile weapon into battle and as maneuverable as possible.
The Flak 41 was a Rheinmetall improvement on the famous Krupp "eighty-eight", resulting in a more powerful version than any of the previous ones. Only very few numbers were produced, but this prompted Krupp to respond with another prototype which ended up becoming the feared Pak 43 & KWK 43 - mounted on the Elefant, Jagdpanther and the Tiger II.
Sd.Kfz. 6/2 at the Temple of Zeus - Athens May 1941
B-26 Marauder Bomber Hit By Flak over France 9th Air Force