"smallfox if what you say is correct, why haven't BMW, Mercedes, VW charged 10% more for their cars for the last xty years?"
If you look at the prices, VW are usually higher priced than the competition, for example the VW golf starts at about £17.5 K and the same class Vauxhall's and Ford's begin at £15, 000 and £13, 500 respectively. In fact when you start to look around other brands you get a lot more bang for your buck for the same amount of money, yet the VW is one of the leading sellers in that market/price range.
BMW, Mercedes and Audi charge about the same as each other. Jaguars are historically slightly cheaper. Again, the base model BMW, Merc and Audi are usually significantly more expensive than the other leading brands like Ford, Nissan, Toyota and Honda in the same size car market.
The Sunderland plant is important to the company, its why it gets investment, but the single market, which takes 70% of the product produced there is as important.
For example last year the plant produced 240,000 QashQai cars of this 168,00 went to the EU. This is why the NMUK management are stalling a little at investing in Sunderland as the new plant.