Both VW and Audi have a big shortage of cars at the moment. They ceased production of models due to the economic down turn, but now things are picking up, they have limited stock of built cars to give to dealers and management to run as demos and so the cars those people are in now (which would be on forecourts around the country) can't be freed up. It also explains why certian models like the Scirocco and Golf GTi aren't avaliable from factory order until Feb 2010...
Bit of a forecasting problem by the Germans!!
All of this has a knock on effect as people can't trade out of there Mk4's, Mk5's etc as they have nothing to get into....
Used car prices have also gone up as new prices have done also due to the Euro / Pound exchange rate....