Recently purchased retractable seat belts for my '83 FJ 40 and struggling on where to mount. Running the hardtop without the roll cage and long bench seats. Mounting hardware supplied looks to be for the roll bar attachment points which I don't have. If I mount at the back of the seat the seat belt extensions stick out so far the belts don't hold tighten on smaller people and lower ones interfere with folding the seats up. Any suggestions? Pictures greatly appreciated.