XT-M5-QS is correct. I don't know what's up with the Owners Guide, but the Ford specification, WSD-M2C200-C, is correct and corresponds to the Ford part number XT-M5-QS not XT-11-QDC. Motorcraft states that the Dual Clutch fluid to only be used in the DPS6, which is the automatically operated manual in the Fiesta. Motorcraft does not provide any technical information on the fluid, so it's hard to tell how applicable the fluid is to the GL-4 75W90/WSD-M2C200-C.
2012 Ingot Silver Mustang - 3.7L V6, Performance Package (traded)
2012 HP White Mustang GT - 5.0L, Premium, 3.73 rear end