Aston Martin DB11 Owner's Handbook Manual page 50

Seat Back Release
Caution: Make sure that the headrest for the seat does not
hit the sun visor. The seat can cause damage to the sun visor
or the sun visor mirror.
Pull the release strap (A) to release the seat back.
Pull and hold to move the rear of the seat forward.
Push the rear of the seat into position to lock it in place.
A warning message will be shown in the instrument cluster if
the seat is not correctly locked back into position.
3.4
Before Driving
The driver and front passenger seats include non-adjustable head
restraints, which limit the rearward travel of the head in a rear
impact and may reduce whip lash injuries. When sitting in the
seats make sure that the seat back is in an upright position and
that the rear of the occupant's head is positioned in the centre of
the head restraint area. The head restraints are most effective
when the distance between the rear of the occupant's head and
the head restraint is kept to a minimum.