I don't think Hitler ever owned a car while he was in office. He could not drive so why would he own a car?

He always traveled in a convoy, so he had a driver. And he would likely ride in whatever car was correct for the moment.

One of the G4's had a passenger seat that would fold out of the way so he could stand flat on the floor during a parade, but he would travel from one town to the next either by air or train and would then be driven around in whatever staff car was handy.