There are a few ports supplying UK VWs. Sheerness, Tyne and Felixstowe are 3 I know of - there must be one supplying Scotland at least. Some ships stop at multiple ports for car drop off. The ones that supply port of Tyne (city of Amsterdam/city of Rome/city of Paris) seem to come over to Tyne directly from Emden for first drop off.
Sheerness seems to be by far the busiest destination for VW drop offs, your dealer shoould know which port your car will be transported to and from there you can go on your port's website and look for ships that have come from Emden or that are sheduled to come from there. You can then look on Emden's website (once you have a ship name and callsign) to see when they are departing from Emden.
Because of where Emden is situated (between the hook of Holland and the Denmark peninsula) it seems like all UK bound cars will arrive somewhere on the east coast rather than sailing around the channel and up the west coast (Irish cars probably make that route to east coast Ireland). My Scirocco came from Portugal and sailed to Rotterdam. It was from Rotterdam that all the UK cars went to their individual ports.
We've got a fair few North East buyers here - i'd expect all the Tyne + Wear cars (and probably Teesside too) to be coming to port of Tyne.
For the port of Tyne, the 3 ships supplying it seem to be in an 11 or 12 day cycle.