Hi. I just came across your conversation and I' d like to let you know, that I was in troubel today, because I was driving my german car in the uk without registering it in uk.
i was stopped by a police man today and i couldn't prove an uk insurence. the result was that they impounded my car. he told me that it isn't allowed to drive a foreign car(even it is eu) more than 3 month - and it doesn't matter if you are a student, visitor or whatever - in the uk without registering in the uk.
I have worked in uk since may and have got my car here since october, what he couldn't believe. he said i have to prove that the car came later than me... you see, it was quite complicated! Anyway, now i got my car back, i paid 105 pounds and will register my car as soon as possible. which means: english number plate, english driving licence, english insurence, road taxes etc.
maybe it was just a bad day, but to be honest, i think the police is quite keen on checking foreign cars these days.