of the Wehrmacht's re-armament program they used commercially available cars (Personenkraftwagen)
and modified them for military use.
In 1934 it was decided to replace the existing
commercially bought vehicles and with a new range of standardised purpose-built
vehicles. It was decided that there would be three classes of Personenkraftwagen.
And that they should have as many parts. In common as possible, e.g. suspension
engines, etc. many manufacturers were involved in the manufacture of Personenkraftwagen,
German Military Vehicles.
Armoured Fighting Vehicles of Germany World War II.
Encyclopedia of German Tanks of World Two.
For a complete list of sources