1" x 2" tube steel for the crossbar with a 1" x 3" 1/4" steel flange welded to the end. 1/4" bolt through drilled hole in the roof rail, new rails barely touch roof on the highest ribs, so we put down some of that foam weather seal. Overall we are very pleased with how it sits, it couldn't sit any lower and is WAY out of the wind, one thing I have not been pleased with are all the aftermarket roof rack solutions always sit up very high in the wind. Its gotta cut down on your gas mileage and increase wind noise. With this setup the Thule sits low and does not make any more wind noise than stock.
With 4 guys, all their backpacking gear for 5 nights in the Grand Canyon driving over the Colorado Rockies on I70 with me pushing it at the speed limit the whole way(the diesel doesnt complain at going 75 up the long passes so hey, why not?) we were still getting 24mpg.
My father and I both have the Thule Evolution 1600(16 cubic feet). With 4 guys and all their gear we were packed in there somethin' fierce. Maybe in the future we will find a good deal on a newer Atlantis 2100(the biggest one they make), that would be nice up there.
Foam to keep it from rubbing and rattlin'
As you can see, when you put it back a little farther the Thule sits back in the windstream from the windshield very nicely.
And the old mans yellow XJ freedom, ironically the wheels that are now on the CRD are the wheels that are supposed to be on his Freedom(one of the reasons we like the freedom package), but instead when we bought his it had the Canyons on it, I'll keep an eye out for another set of the Ultrastars for the future of his Jeep.

_________________
http://www.Colorado4Wheel.com
"Its not about what you can
DO with your Jeep, its about where you can
GO with your Jeep."
Knowledgeable - But Caustic