Cadillac 2010 DTS Owner's Manual page 61

Here is how to install a comfort guide to the safety belt:
2. Place the guide over the belt, and insert the
two edges of the belt into the slots of the guide.
1. Remove the guide from its storage pocket on the
rear side of the seatback.
I n f o r m a t i o n P r o v i d e d b y : 2-29