FORD 2015 Mustang - Manual (Page 187)

Do not tow your vehicle with any wheels
on the ground, as vehicle or transmission
damage may occur. It is recommended to
tow your vehicle with all four (4) wheels
off the ground, such as when using a
car-hauling trailer. Otherwise, you cannot
tow your vehicle.
184
Mustang (), enUSA, First Printing
Towing