The Emission Control System light on my car came on a couple of weeks ago and I took it to the dealer (car still under warranty). The light went off when they took it for a drive. The mechanic told me it was the Diesel Particulate Filter and I should take it for a long drivie on the freeway to burn it off. I had my doubts as that problems has a different symbol light. I did it anyway. The ECS light came back on again 3 days ago. I rang the service dept again to bring it in and the guy told me if it is the DPF and has to be replaced, it's not under warranty because it is due to my driving style. I was speechless. I spend 10-15 minutes (each way) driving on the freeway each day commuting to work. I bet hardly any of the other Audi diesel owners get on the freeway in this city. He said the diesel is not designed for predominantly urban driving. However, I can't see this warning anywhere on the Audi website or their promotional material. Anyway, I am hoping that this guy is talking through his hat as there are 2 DPF warning lights on the car - a yellow symbol and a text message that tells you to read the manual on what to do - i.e. drive on the freeway for 15 mins at around 2000rpm. I have done this twice. Can anyone shed any light on this?