bob
i concur they should be aimed perfect from the factory.
if you're hitting the trees, they MAY be too high.
http://lighting.mbz.org/tech/aim/aim.html
you can still use this procedure to aim your lights. 2.1" at 25' below center mark is correct for u.s.spec
there is a lot of good info at dan's site...
be careful, good luck
peter