Sunroof ? I Think Honda Blackbird Is On The Right Track.
Did The Dealer Mention Anything About Nissan TSB (Technical Service Bulletin NTB11-045), Dated 4/25/2011 ?
These Bulletins Help Dealer Technicians Find/Fix Problems.
This Particular Bulletin Is For 2007 - 2011 Altima Sedans, 2008 - 2011 Coupes, And 2009 - 2011 Maximas.
The bulletin addresses concerns with “ALTIMA AND MAXIMA; SUNROOF FRONT DRAIN HOSE IS KINKED, PINCHED, OR DISCONNECTED,” and discusses wet carpets and water leaking from the suroof/headliner, related to the drain hoses.
Only one page, it tells where to find the problem and how to fix it and includes a color photo of the culprit (kink or pinch in tubing in the lower dash area).
This may or may not be your problem, but is worth questioning. We just don’t know how competent the “leak guy” is.
CSA