The lower trailing arms we used on the Buick are also from TRZ. The TRZ are on top and the AutoFab pieces are on the bottom. The big difference is the Delrin bushing on the frame side and the adjuster on the rearend. The Delrin-equipped bar is more street friendly than one with rod ends (less harsh and less noise). Delrin material doesn’t deflect like poly, which means it’s a far superior material for a street driven car. Some poly bushings cause “stiction”—the bushing momentarily seizes—and that causes all sorts of traction tuning issues. The lower bar adjustment shown in the last photo of this sequence is designed to set the wheelbase on the car (and obviously attempt to simultaneously center the wheels in the wheel well). This setup allows for minute wheelbase changes.