Purchased a 2016 Mustang through the military autosource program (MAS). Noticed the problem the moment I took possession of the vehicle at the port in Bremerhaven Germany. It felt like a slight notchy-ness in the shifter as I drove the vehicle home so I wasn't sure if it was just a normal characteristic or not because I hadn't owned or driven a ford since 1988. It was a noticeable clunk, or thunk when cycling UP through the gears (not downshifting). And... it occurred with the clutch pressed completely to the floor. The best way I can explain the symptom is, if you've ever shifted a car without using the clutch, for instance pulling the shifter out of gear and applying slight pressure into the next gear until the rpm's reach a point that it slips (or pops) into gear, THAT is what I was feeling only not quite as prominent. It seemed to come from everywhere so I couldn't really pinpoint the shifter, transmission, driveshaft, or differential. I could be coasting down the road at any speed and press the clutch fully to the floor and hold it while cycling the shifter back and forth between 1&2, or 2&3, or 3&4, EVERY TIME I'd hit the higher gear it would make that clunking sound... with the clutch to the floor! Over the next few weeks the symptoms intensified. Then, I began to notice a flexing or floating drivetrain feeling accompanied by clicks and clunks. Best way I can explain that symptom is one of two ways. 1) imagine being in a drive-thru line where, as you're inching forward and depress the clutch it feels like the entire drivetrain flexes or bounces back and forth with a slight metal on metal sound. or 2) imagine coasting slowly through a parking lot about 1-2 mph with the clutch depressed to the floor and stop suddenly... again, it felt as if the entire driveline bounced back and forth slightly with a metal on metal tick. I took the car to the dealership, the technician drove it and thought it was perhaps a synchro problem. I left the car. They removed the transmission the next day and determined problems with the synchros. It's now 7 weeks later and absolutely nothing has been done. The dealership is waiting for Ford to make a decision on whether to repair or replace it. Mind you, I am in Germany so a replacement may require additional weeks of shipping once the decision is made. Meanwhile, the cost of this repair increases daily with the nice loaner car they gave me but they don't care because that cost comes out of a different pot of money than the warranty work, so they say. To me, it's just stupid.