Its surprising its on the SRT6 because I was under the impression Karmann corrected the defect after the '04 models (obviously the SRT6 wasn't manufactured until later). I was wary just as you are of the dealers working on the car and they can wear you down with their BS excuses. Here's the basics of the repair... the work it takes to replace the differential is relatively simple and takes less than a day (its done on trucks and 4 wheel/rear wheel drive vehicles quite often). The reason dealers try to through you off telling you its "normal noise" is because the part is around the $3,000 range and when its under warranty it costs them more to fix it (I don't know if this makes sense but its what I have read). I'll tell you how it goes on Monday. I will post it in the other thread I created. Good luck!