why? after some years, the wires do deteriorate and it makes the current supply to the components unstable..could lead to power loss. proper grounding would lead to consistent supply of currents adn you would definitely experience smoother acceleration and the likes. i've seen a friend of mine did it to his 3-series (hmmm..), and definitely there are marked improvements. the grounding kit only costs about 40GBP...and yet, the improvement seemed to cost more.