The dreaded DPF light came on the other day, swiftly followed by the flashing glowplug light, then the Emissions light, then a lovely loss of power. The usual trick of 15 mins in 4th at 2000rpm didn't cure it. One call to Audi Roadside Assistance and they fixed it within 20 mins. Apparently the DPF was 89% clogged. At 90% it can't be reset manually and requires a trip to Audi, and potentially a £1500 bill. Very relieved!!