Hi Mike,
I took off my factory rails and added these (
http://www.prolineracks.com/proline-roof-end-track-slats.html ) in 72-inch length and use Yakima (4 of the pre-Control Towers) per side. I've got the tent mounted, sometimes, and have a 2-foot "basket" up front for extra storage.
Works pretty well. I was concerned about how secure this setup would be, but at the Trophy last year, nothing shifted during the closed course:smiley_drive:
This has given me the whole roof to work with, versus 2/3rds.
Attached is a pic ...