Nice. Yea the video/instructions describe the alternate ways of mounting the tent rails with respect to side or back of vehicle opening, but it likewise enables different mounting options for various roof racks as well. You shouldn't have a problem, once you have it in front of you it'll make sense. I know on my Gobi rack I could have installed the tent rails in either configuration and maintained a side opening. I installed mine at their shop in Santa Cruz and opted for mounting the rails side-to-side, mainly cause they threw out the idea that if I ever wanted to run an awning I could potentially mount it directly to the tent rails, making it easy to take on and off. If you do this you'll want to keep the tent rails a few inches longer on the opposite side that the tent folds open. Either way, goodluck!