I let the dealer install mine on our old H3, never had any wind noise in the 11,000 miles we had that one.
Here is a link on the site about installation
http://www.elcovaforums.com/forums/s...ead.php?t=3576
The below link is listed in the thread above
Scroll down to the off road light bar - he gives a great description on how to do it.
http://www.rausite.com/hummerh3.htm