Has anyone installed this on their car? I have read a lot of reviews for the GFB underdrive kit for the older generations and they all seem to say that the part is of good quality and the engine definitely benefits from it. I see that with this new kit they have changed some things compared to their older version. I am just wondering if anyone has installed this, and if they have, what benefits have they seen? Also, if you have, have you noticed any balance issues or other engine problems that could have been caused by installing this?