Strengthening bush press-fit already front lower arm. By using a reinforcing bushing with excellent high hardness and durability, reducing the bushing deformation during cornering. It is possible to suppress the alignment change due to the movement of the bush, in addition to straight-line stability improvements in the high-speed range, providing a more direct handling and quick steering response. Arm ASSY with press-fitting work is no need of reinforcement Bush. It is the best to refresh the underbody. Until the street-circuit is essential in all stages.