This is Panzerkampwagon IIIV - developed in early 1945
At this time, the great german war machine was hurting for resources and factories to build them in. Here is a picture of the prototype in their remote desert testing area.
It was said the plan was to cause another revolution in warfare similiar to the "blitzkreig" did years earlier. It was said to incorparate the "boom-boom over the head warfare".
many of the features
......steel wheel rims for overland operations
......"Walmart" protective armor for the driver
......manual "Craftsman 32mm" weapon system
......manual "huffy drive" w/single speed transmission
Thank goodness this nasty weapon never made it past the prototype - who knows how it could have changed the outcome of the war !