For the last few months I've had a feeling my engine was feeling down on power (I've reached down a number of times to check the handbrake wasn't on), and also running a tad rough. The run back from the Alps last weekend confirmed it for me, when it was cruising along but dropping down to 6th to get up hills I know it has gone up in 7th before. Its a 140 DSG Kombi with 68k on the clock. Any thoughts? I was at the dealership yesterday for its MOT and I mentioned it and they put it on the computer but nothing was found. Is there some additive I could use? Is it a prelude of something to come?