Buick 1995 Century Owner's Manual page 199

Sedan (Securing the Flat Tire)
EPLT
1.
2.
3.
4.
Place the flat tire, air valve up, in the tire storage
area.
Remove the extension bolt from the jacking tools
bag. Secure the tire by inserting and tightening the
extension bolt through the center of the tire into the
storage area floor.
Place the spare tire cover on the storage area, with
the jack face down over the hole in the center of the
board.
Insert the center retainer bolt through the jack and
secure it by turning the bolt clockwise.
The cover will not fit flush when a flat tire is stored in
this location.
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