Both rear window defroster elements separated from the rear window. Considering I don't use the rear defroster very often in Florida, and I don't open just the glass of the liftgate, I wouldn't think this would've happened.

2015 Tahoe 37,00 miles and the rear window defroster wired separated from the window which the dealer say is common. But the only fix is to replace the entire window for $850 and the dealer says it is not covered by the Certified Used Car warranty. From my readings this has been a problem for years, going back to 2007 at least.