You can only do this if you have a MyFord/Lincoln Touch system in your vehicle. A phone must be connected and the car must be in park. Press PHONE > MESSAGING > SEND TEXT > Dial the phone number you wish to send a text to and touch OK. You'll see a list of preset messages listed, click one that you don't use very often, then press EDIT TEXT and use the keyboard to change the message. In the future, you'll see that message saved in your preset list.
No mustang to date has MyFord Touch.
2012 Mustang GT Premium Kona Blue W/ 401A Trim
Electronics PKG, RR Sensing/Security PKG, HIDs PKG, Comfort PKG, Brembo Brake PKG, Glass Roof, Rear Camera