Had two ..one on my 305 BHP 20i E89 and now on my 550 BHP 35is E89..fab bit of kit..when you are hooning and things are less than optimal for whatever reason these babies help you in ways you can't imagine!
Watched the video yesterday Very pleased when I got mine fitted ( not Quaife ) . Certainly makes a difference and as you mentioned when you were lining up for a bend and had to adjust it due to a car coming the other way they can be quite a subtle improvement not just for spinning up the rear wheels . Much as [ref]B21[/ref], has also said .