Yes, sometimes Nissan is willing to help cover part of the total repair cost via goodwill.
Nissan used to list some of their warranty extensions on specific systems of specific cars at http://nissanassist.com/web/
, but it seems that site is quite bare now, for whatever reason. For a flavor, see https://web.archive.org/web/20130503003 ... php?menu=1
or https://web.archive.org/web/20150912013 ... t.com/web/
In the case of my mother's Altima Hybrid which unfortunately has a known problem of getting carboned up in certain cases (there's a TSB on it), When she was out of powertrain warranty, she hit the symptoms (CEL). Supposedly, the DTCs and diagnosis meant that she needed a new cylinder head.
(TSB mentions that too.) Dealer (i don't like their service dept much, I'd have rather gone to one I like better) was able to get Nissan to cover the part but not the labor cost.
Unfortunately, the repair bill was still pretty high. IIRC, it was on the order of $2K.