Ford Mustang Owner's Manual page 107

Seatback Recline
Front seatback release levers
It is necessary to use the seatback release when
folding the back of the front seat forward for
rear seat passenger entry or exit. This release
handle is located on the lower outboard back of
the seat. The seatback locks automatically when
returned to the normal position.
To allow rear seat passenger access, use one
hand to pull up on the release handle then use
the other hand to push the seatback forward.
Check to see that the seat and seatback
are latched securely in position. Keep
floor area free of objects that would
prevent proper seat engagement. Never
attempt to adjust the seat while the
vehicle is in motion.
106
WARNING