I have an 08 FSI, and I did the tweak a while back and it did seem to help a tad, but I already had an LSD at the time so it's hard to say if I had some placebo effect going or not. It's designed for use in the 3.6 / 3.2 FWD passats
What size AN line did you use and what connection/adapter did you use where it comes into the engine bay? Did you use one of these quick connect fittings