One problem related to manual transmission floor shifter has been reported for the 2012 Ford Mustang. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2012 Ford Mustang based on all problems reported for the 2012 Mustang.
Binding shift linkage, unable to shift. Occurred when merging unto freeway and shifting from 2nd to 3rd gear, nearly run into by following traffic, had to coast to shoulder and nearly stop before able to shift into any gear. In addition, the transmission grinds when shifting to 5th gear. The binding linkage has occurred several more times since the initial problem. I am 67 years old and have had many vehicles in my lifetime with similiar drivetrains and have not had this type of problem with any of them. I presently own 3 other vehicles with manual transmissions, all floor shifters ( one 4 speed, one 5 speed, and one 6 speed), and they have never had this problem. I believe the linkage and transmission is defective and am returning it to the dealer in the near future for a warranty claim. I have delayed the warranty claim for several reasons,number one: the vehicle is one of six I presently own and it sees very little use and has very low miles on it, number two: I have been able to avoid damage from the grinding by skipping 6th gear, number three: the dealer is not real close to my residence so I have delayed the trip there until logging enough miles to justify an oil change at the time of investigating the grinding and linkage problem. The vehicle was purchased new on 6-1-11 and had approximately 10 miles on the odometer when received by me. The vehicle has the getrag 6 speed transmission. The spacing between gears seems excessively close and may contribute to the problem.