big hunk of metal that sucked away your money.
the 120 would be better spent towards springs or a rear strut bar.
of all the places the chasis is gonna flex, its not gonna be right at the door frame.
edit- i just saw you already have lowered your p5. so i'd say get a rear sway or strut bar instead of the floor bar.
in reality, since its a universal piece, i doubt it can get as tight as it needs to be inorder to reduce flex.