The R35's chief engineer Kazutoshi Mizuno recently retired, you see, and Nissan
is apparently having trouble filling his shoes. Beyond that, however, Nissan's CEO Carlos Ghosn has not given the project the green light. Apparently Ghosn can't justify the business case based on the sales figures for the current GT-R, even as a loss-leader halo car. Projects like the Nissan Leaf are apparently his greater focus given the current state of the industry. It's worth noting, for comparison's sake, that Nissan's allied automaker Renault
(over which Ghosn also presides) is reportedly preparing a new Alpine sportscar while also developing a full range of EVs.