Cadillac CTS 2008 Owner's Manual page 116

Automatic Transmission Operation
The shift lever is located on the center console between
the front seats.
P (Park): This position locks the rear wheels. It is the
best position to use when you start the engine because
your vehicle cannot move easily.
2-38
There are several different
positions for the shift lever.
CAUTION:
{
It is dangerous to get out of the vehicle if
the shift lever is not fully in P (Park) with the
parking brake firmly set. The vehicle can roll.
Do not leave the vehicle when the engine
is running unless you have to. If you have
left the engine running, the vehicle can move
suddenly. You or others could be injured.
To be sure the vehicle will not move, even
when you are on fairly level ground, always
set the parking brake and move the shift lever
to P (Park). See Shifting Into Park (Automatic
Transmission) on page 2-45. If you are pulling
a trailer, see Towing a Trailer on page 4-30.