The headliner being cut too short was a problem on mine from the 1st mile. I took it in and had them replace it, but ended up scratching and scraping up all my interior plastic pannels they removed to install. This is the link to the picture I posted about it.
http://www.the370z.com/nissan-370z-g...ml#post2299230
Just make sure that when you get it back, you inspect the crap out of it! My pannels were scraped up, the pannels did not sit flush anymore and had gaps, the new headliner was mis shaped and bent in the corners, and the top seatbelt feeds were installed backwards!
First, the service tech tried to say all the cars have gaps like that and tried to show me another car to prove it. I said that may be true, but mine did not when I brought it in and I wanted it back to the same exact state that I provided it in.