hey there mpjoneill, first off the
Thule 897XT Hullavator kayak rack is not compatible with the Toyota FJ Cruiser roof rack cross bars, or any factory car rack bars for that matter. the 897XT will only mount on any of Thule Racks base rack system load bars - either the classic square loadbars or the new elliptical Rapid Aero bars type - or Yakima Racks base rack round crossbars. You will want to install either the
Thule 450R Rapid Crossroad roof rack system (uses the low profile elliptical Thule Rapid Aero bars) or the
Thule 450 Crossoad roof rack system (uses the square Thule bars). Both of these base rack systems work in exactly the same fashion by attaching right to the Toyota FJ Cruiser roof rack side rails. You can then simply mount the Thule 897Xt Hullavater kayak carrier to the 450 / 450R CrossRoad load bars and you are all set to load and go!
This system won't really make any distracting noise either. If you don't want to have the rack system mounted on top when you're not hauling a kayak then it's not that time consuming to simply remove the kayak rack and the base rack system. The nice feature about this system is that you can easily transfer it to any other car that has side rails if you ever have the need.