Now there is one concern to worry about, there is an old version that was thought by some to be "too aggressive" and very sensitive for the higher hp cars like the CLK55 AMG, C32 AMG, CLS55 AMG, and including the SLK32 AMG (SRT-6). Now there is a 2nd version, which is a little more tame, but will still bring more responsiveness than a regular DBW reset. IMO, I believe it is a must for the non-supercharged xfires to have the older version. For those of you who have an SRT-6, it is up to you.