ive not sorted the roof mech out yet, but as all the frame work was out on show I had a really good look and have a good idea now what the problem is. Also Ray says to keep the roof up for 3 to 4 weeks (hard to resist ) just so that the material has time to strech as its very tight over the frame. Think about it....my oem roof was 10 yrs old and had ten years of moving, stretching etc so what happens is that eventually becomes loose and is concave when taken off, as it was taking shape of the roof. New roof is based on oem templates so its very tight as it came out of the factory. Considering Nissan wanted 1500 bucks lol. So yes...very very pleased. I have got close up pics which Ill post asap