One problem with establishing 'ownership' is that most of these cars were never titled to the individual they were assigned to. They belonged to the German Army or Air Force but were used by normally one person.

The six-wheeled Mercedes 'G' would be an example. Hitler loved these cars and was often filmed using them, but the cost was so high at DM 7,500 each the Nazi Party could not afford them. So Hitler saw to it that the Army ordered them and provided them to him.

Mercedes built the cars for the Army to begin with, but the Army balked at the price. Therefore Mercedes just waited until Der Fuehrer showed up at the factory to see something else and just let it slip that such a car existed. It was love at first sight and the Army wound up buying some anyway.

Hitler did have one G that was a parade car with a front passenger seat that folded out of the way so he could stand up and wave at the crowd, but Hitler himself never owned a car. It would be like saying the US President 'owned' the car the Secret Service provided for him.