You already have rails? Mine doesn't and can't get them installed with my sunroof. So looking for a work around.I have a Thule rack for my kayaks. There are, for all rack systems, specific measurements from top of windshield to front of rack "towers" (the legs), and the distance from the back door edge to the back end of the back tower. My Rio 5 had triangles in the inside edge of the door jams for locating the racks.
My racks came with 4 "T" wrenches with plastic handles. The manufacturer specifies the number of turns to install. It's quite a bit of turning, but it's solid. These can be removed or left in place, concealed behind the towers' outside faceplate. Unturn (if you will) these screws to remove the unit from the car. On the other side of the tower, a plastic flap gives access to help open the tower for removal.
My advice is to use a towel or such near the edge of the car when you're installing or removing the racks. Just because sometimes things move, and the towel saves the paint.
So, in my opinion, and the roof rack companies, there are removable roof racks. Not that you'll want to put them on and off a lot. I almost always have a kayak on, except in the winter. I remove the rack in late fall and lube all threads then. Leave them on if you want them to rust to a fixed position on your car. Come spring, it's lubed, easy turning to re-install.
I've go pix on this site of my 2016 Soul with the racks and boat ... somewhere.
Just remember when you're installing, be patient with yourself and follow the specifications. You could mark inside the door for location (tape, pen) if it's gonna be a lotta on/off stuff.
Have you seen this? http://www.kiasoulforums.com/29-how-diy/12580-my-roof-rail-bike-rack-solution-pics.html
or this? 2 pages http://www.kiasoulforums.com/26-soul-accessories/8110-o-e-m-roof-rack-my-kia-soul.html
or 2 pages http://www.kiasoulforums.com/26-sou...-roof-rack-system-soul-no-drill-solution.html
I paid $300 plus tax for Kia cross bars to go on the factory rails. They were flexible, and one screw affixed them at each end. It was scary to drive with an 18 ft kayak.
The Thule cross bars are square-sectioned, don't flex under load. The tower system is rock solid.
This from a guy who's had forty (Canadian spelling) years of canoe, kayak, etc hauling. I hauled roof-topped kayaks one day when I passed two of those big, solid, welded, multi-boat canoe trailers. Each was many miles apart and they were not together at all. Each of those trailers' welded trees snapped off. I know the Thule system works. If you want to just carry light stuff, maybe the Kia racks are o.k. But even plywood seemed risky to me. I gave them away free.