Cadillac 2009 XLR Owner's Manual page 364

7. Locate the vertical headlamp aiming screws, which
are under the hood near each headlamp assembly.
The adjustment screw can be turned with a
6 mm male hex.
9. The top edge of the cut-off should be positioned at
the bottom edge of the horizontal tape line.
6-44
8. Turn the vertical
aiming screw until the
headlamp beam is
aimed to the horizontal
tape line.
10. Make sure that the light from the headlamp is
positioned at the bottom edge of the horizontal tape
line. The lamp on the left (A) shows the correct
headlamp aim. The lamp on the right (B) shows the
incorrect headlamp aim.
11. Repeat Steps 7 through 9 for the opposite
headlamp.