With this applicaion we used TP54 Thule Track with 430R Rapid Aero Towers and RB53 Rapid Aero bar. The tracks are mounted by first drilling some holes to drop in some flare nuts/bolt anchors and then the tracks are bolted down and silicone is used to seal the holes. The track is permanent but the rest of the setup (crossbars) can be removed. The track allows for the crossbars to be repositioned depending on what is being carried. It also adds to the strength of the rack. See rackattack.com for more info.