Please bear in mind that I'm no mechanic, so wouldn't really know my way around the full workings of the car.. I've got an 03 A4 Quattro Sport, it feels sluggish, like there is something holding it back. It is not freewheeling like my a4 TDI, if I go to move off and engage the clutch it slows to a stop. I've had a mechanic check brakes and they are not sticking.. Any thoughts on what else it could be? Any ideas for what I should be looking for or researching?