I've aimed my '97 E320 this way: Pull the car into a level space and
absolutely perpendicular to (facing) a wall. Tape or tack a one inch
wide contrasting strip vertically to the wall, directly in front of each
headlamp. Measure the distance between the lamps' center and then the
distance between the strips to ensure the strips are accurately located.
Then measure from the ground up to the center of each headlight and
transfer that measurement to the wall and add a horizontal strip at that
same height to the right of each vertical strip.
Roll the car straight back so the headlights are 20' from the wall.
Those marks on the wall are the target to which you should aim the
The mechanical adjustments are made above the headlamp.
One is height, the other left/right direction. The beam's height should
not exceed the horizontal strip and the left/right should be on or
slightly to the right of the vertical strips.
The Owner's Manual gives similar instructions but has it reversed, as if
written for cars driven on the left.