Ford 1996 Crown Victoria Manual page 140

Positive Location Floor Mat
When installing or removing the driver's side
floor mat you must attach/detach the positive
location grommet from the hook on the floor.
The hook is just forward of the center of the
driver's seat. This is done by rotating the
grommet one quarter turn, slipping the eyelet
onto the hook, and sliding it to the floor.
The positive location floor mat hook
147