Wait til you see your mileage with awning! I am sure it can be done but I wouldn't trust the side loading moment on just one rail, especially if you are not running crossbars. The roof rack and crossbars are designed to distribute the load down to the anchor points. My guess is if you hang an awning on one rack you will break the lugs off the roof channel. There is a lot of force on that awning when cruising down the road. All of that force is going to be side loaded to three 10 or 12mm (I forget) bolts on one side......that is a recipe for disaster and an expensive roof structure fix!