Aston Martin DB 9 2010 Manual page 44

Push the tongue into the belt buckle
latch until a positive click is heard.
Pull upwards on the diagonal belt to
make sure that the latching is secure
and to remove all slack from the belt.
Finally, double check that the lap belt
is installed snugly, low down across
the hips, and that there are no twists.
If it is necessary for an occupant to
adjust their seat or seating position
during a journey, the belt tension
might be disturbed.
3.14
The occupant should therefore
(as soon as it is safe to do so)
gently pull down the shoulder
run of the seat belt to create
some slack and then
immediately release it to re-
tension the belt for the new
seating position.
Seat Belt Unfastening
Depress the button on the buckle. While
holding the seat belt tongue allow the belt to
slowly retract to its stored position.
Seat Belt Fastening (Child)
Warning: An infant or child that is not properly restrained can
be seriously injured or killed in a crash. Seat belts are designed for
adults and larger children; infants and smaller children must be
restrained in an approved child safety seat.
Make sure that there is no slack in the webbing and the restraint fits
the child snugly across the rib cage and hips. These are the parts of
the body most able to take the force of impact.
The lap strap should pass across the top of the child's thighs, bearing
on the pelvis, not on the abdominal area.