I am not sure how well known of an issue this is, but I recently had a major coolant loss while driving for no apparent reason. I did some searching and found vague mentioning of a bolt that caused leaks on New Edge mustangs on the hose that connects the rear passenger head to the heater core. Well after removal of the hose, I found the aforementioned bolt and the hole it had worn through the hose. This was annoying for two reasons in particular: the problem could have been easily foreseen and prevented, as the setup was a ticking time bomb, and ford discontinued the production of the hose that needed replacing. So just a warning to everyone: please check this hose and make sure that bolt isn't trying to shove its way through that irreplaceable heater hose. I fab'ed up one of my own for replacement and went through the tedious coolant burping procedure, which solved my leak. Safe driving.