Reference to Holson Adi's comments, I had this same experience too, even at a big Mercedes outlet in an upmarket area. Tell you how they do it. The owner will drive the car around before you turn up so the big jerk is gone by the time you take it for a drive. After that it changes normally with only a small jerk which normally will not upset anyone except a Lexus owner. The Mercedes sales outlet gave me a story about the car being out of fuel and needed topping up before taking me for a test drive. He disappeared for about 30 minutes supposedly to a petrol station just around the corner. You bet he took it for a long drive to get rid of the huge jerky change as it was cold and not tested that day. What can I say??? The car operated normally and I found nothing against it. The place I got my car also did the same thing because they knew I was coming at a certain time. It didn't jerk until I took it home and started off next morning and they said nothing was wrong. Said they all do that. However if told before, I would not have signed the contract!