Cadillac 1998 DeVille Owner's Manual page 40

The right front passenger's side impact air bag is in the
passenger's door.
If something is between an occupant and an air
bag, the bag might not inflate properly or it
might force the object into that person. The path
of an inflating air bag must be kept clear. Don't
put anything between an occupant and an air
bag, and don't attach or put anything on the
steering wheel hub or on or near any other air
bag covering.
1-25