All VW and Audi cars leave Germany from the port of Emden in northern Germany and go to either Sheerness, Grimsby or Tyne depending on the dealer's location. Cars are transported from the various factories to Emden by train.If you are interested you can track the ships leaving Emden on this website
'EMDEN' Departures & Arrivals in Port - AIS Marine Traffic. The vessels VW/Audi use are called Weser Highway, Neckar Highway, Main Highway, EMS Highway, Isar Highway and Schelde Highway. They are all operated by the KESS company and it takes them just under 24 hours to get from Germany to the UK.