I have a 2006 A3 2.0 TDI 140PS Quattro. For a while now it has been running lumpy and the car has been bouncing up and down when sat at traffic lights on idle. It had the Dual Mass flywheel and clutch replaced in February which made it run marginally smoother and took away the obvious noise from a failed DMF (scraping noise under the bonnet) Since then though the problem has just got worse and worse. When you first start the car and it's running cold it's fine, no real shake/vibrations or anything. As soon as it warms up it starts running horribly lumpy. This is made 20% worse if you're stopped on an incline (uphill or downhill). Once the car has warmed up, if you switch it off and then on again it also starts up very rough when the engine initially turns over, often giving 2 or 3 big jolts as the engine kicks in, then followed by a puff of smoke. There is also a knocking from under the dash area when steering at low speed or parking, this has been around for months and from what I can gather doing research is possibly the lower end of the steering rack also on it's way out? Any help on this would be a huge help, it's going back in to the garage on Wednesday and I really want to try and financially prepare myself.