sorry to hear you are still having issues. In all honesty i can't add any more advice than that that i posted last time but i'll give it a go.
Zugara is correct the roof material is not covered by the warranty but the mechanics are. But The nissan garage where i bought my 350 replaced all the seals as an act of goodwill as the leak was unacceptable.
I was more careful with the 370 purchase. When i bought the car i made them confirm that any potential issues with the hood and roof mechanics would be covered by the warranty as i had seen the problems some owners had. The only information they could find was the canadian warranty which mentioned the whole car was covered. As a result they agreed they would cover the roof material. Since then they have kept their word and everything i have asked for they have fixed or are paying to be fixed.
You shouldnt need to return to the same garage. If its a nissan warranty you can take it to any nissan garage - try that. Another place may be more knowledgable. Take my recent example, went to one nissan garage and a month later they didnt know how to Fix the roof. Drove into a nissan performance specialist monday and without even looking at the car they diagnosed the problem and said its a small job and they can fix it under warranty. Its all about finding the right place.
I would say though that if the hood had those rips when you bought it the garage could turn around and say you should have known what you were buying. Pity they have gone back on their word as i thought a 50/50 split of the bill was generous.
Given the huge cost of a new roof i would perhaps enquire as to what this non standard roof is going to be, it may be fine. Have you contacted a specialist roof repair place yet to get a quote? Perhaps you could then go back and ask them to pay halfof that.
Hope you get it sorted.