Grahamc - thanks for the informative response. I am from Sheffield and the only GTR specialist nearby is a local NHPC that's about 20 miles from me that I'm aware of, where abouts is sly based?
I think that if I was to own a GTR I would have the 2 services per year, even if one is just an oil change and check over as you've mentioned for piece of mind. Obviously to get a 09/10 GTR my 40k budget would probably be all gone, which is why I've considered other cars I.e the c63. I think most important thing is to get out there and test drive some. All that being said it is a dream to own a GTR, my partners next door neighbour has owned pretty much every car under the sun (Aston Martin, Bentley, Porsche etc.) and his favourite of all was the Nissan as an all rounder.