Just been out in the car for a short run, everything ok initialy but after a couple of mile I put my foot down and not much happened. Experienced this once before a couple of weeks ago. Acceleration is very steady, no kick down etc. Pull over and stop the engine, restart and bingo, everything back to normal Was serviced by MB in November and been running perfectly. Not had a look at anything yet, but thinking of checking MAF sensor. Will probably end up taking it to MB for code reading.