Cls320 - a couple of flat spots under heavy acceleration then limp mode? Did a heavy acceleration during which I got 2 noticeable flat spot judders but continued ok. After thinking that wasn't right, tried this again then noticed I could put the foot flat to the floor with no acceleration at all - no warning lights or noises. Switched off, then on again and tried it again and the same. Just had it 3 weeks after buying it with 94000 miles. Booked in for a test next week - but looking for a 2nd opinion as to what it could be? Car was into local Merc garage and Star found an event related to turbo boost 'thingy' - could it be the turbo boost controller alexanderfoti mentioned at the start of the thread. Been told this can stick if car has been sitting around on forecourt, which it had until I bought it 3 weeks ago. Anyway, they treated it - suspect clean/lubrication - and it appears to be ok now as I tested it 3 times and all of them passed - whereas last week when i tried it all attempts failed. Garage have told me to take a week to check it is indeed fixed. Will let you know... I had the same problem with my car, running fine, accelerate hard- limped home- car seemed to reset and was fine until the next time-after this happening 2-3 times I took the car back to the forecourt- Turbo