Cadillac 2005 STS - Manual (Page 362)

Changing a Flat Tire
If a tire goes flat, avoid further tire and wheel damage
by driving slowly to a level place. Turn on your
hazard warning flashers.
{ CAUTION:
Changing a tire can be dangerous. The vehicle
can slip off the jack and roll over or fall on you
or other people. You and they could be badly
injured or even killed. Find a level place to
change your tire. To help prevent the vehicle
from moving:
1. Set the parking brake firmly.
2. Put the shift lever in PARK (P).
CAUTION: (Continued)
CAUTION: (Continued)
3. Turn off the engine and do not restart
while the vehicle is raised.
4. Do not allow passengers to remain in
the vehicle.
To be even more certain the vehicle will not
move, you should put blocks at the front and
rear of the tire farthest away from the one
being changed. That would be the tire, on the
other side, at the opposite end of the vehicle.
5-72