I think Auto is the word for "car", and Fahrzeug means vehicle. But is that any vehicle? Motorcycle, plane, boat or train? And what about metaphorical vehicles? We here in the states sometimes refer to business deals as vehicles. Say for instance using the purchase of a company to gain control of some properties or rights that are totally unrelated to the business being purchased. It is a method or means of transfer. Do Germans use Fahrzeug in a similar fashion?