Buick 2005 Century Owner's Manual page 59

If your vehicle has one, the driver's side impact air bag is
in the side of the driver's seatback closest to the door.
CAUTION:
{
If something is between an occupant and an
airbag, the bag might not inflate properly or it
might force the object into that person causing
severe injury or even death. The path of an
inflating airbag must be kept clear. Do not put
anything between an occupant and an airbag,
and do not attach or put anything on the
steering wheel hub or on or near any other
airbag covering. Do not let seat covers block
the inflation path of a side impact airbag.
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