Ford Mustang Owner's Manual page 155

If the engine is idling while you are stopped in
an open area for long periods of time, open the
windows at least one inch (2.5 cm). Also, the
heating or air conditioning system should be set
to any function except MAX A/C or AUTO.
If you use the heater, set the fan speed on
MEDIUM or HIGH with the function control
knob at any desired position.
If you use the air conditioner, set the fan
speed on MEDIUM or HIGH with the
function control knob at any position except
OFF and the temperature control lever at
mid-position.
Pushing
Vehicles with automatic transmissions cannot be
started by pushing. Vehicles with manual
transmissions should not be push started due to
possible catalytic converter damage. Follow the
directions under If Your Vehicle Needs a
Jump-Start.
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