Cadillac 2004 Seville Owner's Manual page 360

To reinstall the rear seat cushion, do the following:
CAUTION:
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A safety belt that isn't properly routed through
the seat cushion or is twisted won't provide
the protection needed in a crash. If the safety
5-100
CAUTION: (Continued)
CAUTION: (Continued)
belt hasn't been routed through the seat
cushion at all, it won't be there to work for the
next passenger. The person sitting in that
position could be badly injured. After
reinstalling the seat cushion, always check to
be sure that the safety belts are properly
routed and are not twisted.
1. Buckle the center passenger position safety belt,
then route the safety belts through the proper slots
in the seat cushion. Do not let the safety belts
get twisted.
2. Slide the rear of the cushion up and under the
seatback so the rear-locating guides hook into
the wire loops on the back frame.
3. With the seat cushion lowered, push rearward and
then press down on the seat cushion until the
spring locks on both ends engage.
4. Check to make sure the safety belts are properly
routed and that no portion of any safety belt is
trapped under the seat. Also make sure the seat
cushion is secured.