I have a 2008 Subaru Outback with factory...
I have a 2008 Subaru Outback with factory side rails, without crossrails. What do I need to get to be able to use the Sky Box 16?
This is the box that I have on my 2000 outback. I think the side rails are slightly different on the newer generations, but for my setup I have 4 RailGrab Towers (http://www.backcountry.com/yakima-railgrab-tower), and a set of round Yakima crossbars, I think they might be ~48" but not positive. The size of those that you'll need will depend on if you plan to put anything else on your roof (I also have a bike rack up there, so I needed some wider bars). Also, you'll probably want a 4-pack of SKS cores to secure the bars to your vehicle.