The way I understand it, there are several ways a safety recall through the NHTSA can be issued. First, the manufacturer can voluntary contact them and initiate a recall, out of the blue. BRP did this for the initial Spyder brake issues, and for the recent RT wiring problem. Second, there can be complaints to the NHTSA or the manufacturer, and the manufacturer can voluntarily initiate a recall. Third, the NHTSA can lean on the manufacturer, usually after complaints and an investigation, and the manufacturer initiates the recall under pressure from NHTSA. This was the case with the Toyota gas pedals this last time around. Finally, The NHTSA could, as far as I can tell, initiate the recall by itself, but this would involve actually pulling the vehicles off the road, since no fix would be worked out with the manufacturer. Obviously, this would rarely, if ever, happen.