Rocky Road offers 2 sliders for the FJ Cruiser. Both bolt on using the factory mount points.
"To begin with, we use 3/16″ inner hitch steel to make sure your bars do NOT bend! Anything other than hitch steel is just plain flimsy. Most other rocker bars are made from thin 1/8″ wall tube material. A lot of shops refer to these as Nerf bars or even ‘super’ nerf bars… an appropriate name since they will offer about as much protection to your vehicle as a Nerf toy product would. "
Basic Rock Rail
Picture shown below is a basic example but does not show the FJ mount points.