Mounting the Specialty Raingutter Feet is actually quite easy. Once you load the bar onto the feet, you can place each foot on either side of the car. The bar will slide easily through the foot to determine the proper amount of bar extending outboard of the tower. Once you have things in place, turn the locking knob to the right, and the resulting tension, will not only tighten the foot to the car, but will also tighten the bar inside the foot.