The rear lower bar from Luxon connects the opposite sides of the rear part of your Genesis Coupe's chassis together with high tension lever arms to increase the suspension's resistance to roll in turns.
This high quality suspension modification reduces increased weight on the outside tires while hard cornering, which drastically improves handling as well as steering. It causes the body of the Genesis Coupe to remain flat through a turn so that the weight stays distributed evenly on all four tires.