When I went to the dealer and told them I wanted a new roof putting on I mentioned that I had read on forums in the states that people had, had bad / shoddy work done and had to go back with the roof for it to be corrected. Dealer was very good said the GTR specialist would do the work.
Must admit I was apprehensive going to pick the car up but on the face of it, it looks like the roof when new. Fitment looks good and tried the roof a couple of times and appears to work ok and all fits back into place.
I am going to have a good look round it this weekend just to make sure.
I am sure that I read on the US forums that Nissan had issued a TSB re the door catching the roof on the edges and that there was a fix for this.
Nissan should sort the problem out under warranty, had no issue with my claim.