1999 Cadillac DeVille Owner's Manual - Page 307
1999 Cadillac DeVille Manual
Page 307 highlights
yellowblue A. Horizontal Aiming Screw C. Indicator 1. Turn the horizontal aiming screw until the indicator is lined up with zero. B. Vertical Aiming Screw D. Level Bubble 2. Turn the vertical aiming screw until the level bubble is lined up with zero. 6-37