Cadillac 2005 XLR Owner's Manual page 66

To open a door from the inside, press the button in front
of the door handle and push the door open.
If power to the vehicle or the keyless access transmitter
is lost, there are two ways to open the door.
2-10
If you are inside the vehicle, use the door release
handle located on the floor next to each seat. Pull the
handle up to unlock and unlatch the door.