Ford Mustang 2009 Owner's Manual Supplement page 19

Roadside Emergencies
Wheel lift
When towing the Shelby GT500, for front loading, the front tires must be
16 in. (41 cm) higher than the rear.
For rear loading, the rear tires must be 14 in. (36 cm) higher than the
front.
19
2009 05+ Mustang (197)
Supplement
USA (fus)