Welcome, best wishes for your future lives on Corfu. You have found the best site by far to get answers and support visa vi Corfu stuff.
As to the 'car' situation, it is a topic that comes up again and again, it is more complicated than it seems, a truly Greek approach to the subject.
My advice, do not leave your car on Corfu for longer than 6 months (you can extend this by 3 months I believe at local police office), get the correct paperwork from Greek embassy in London when time comes and bring car in then.
However my advice might be out of date now on this extension although if you fall foul of any current regulations (or interpreted regulations to be more precise) then be prepared to lose your vehicle.