Hey well where to start. I bought a 2006 2.0tdi s-line at the end of december, with 42k on the clock. Couldn't compare it with the peugeot 307 i previously owned, always wanted an a3 and seeing as im 20 i was in dreamland. for the past couple of weeks while driving on the motorway i felt a sudden 'jerk' now n then while travelling at around 65-80mph. i didn't think anything into it as i've got a service at preston audi coming up on wednesday. 49K on the clock now and i was driving from preston to london the other day, 30 miles away and while doing 80mph the car suddenly loss all power, i had no idea what happened, no lights came on. made my way to the hotel and read up on the forums that the car had gone into limp mode. the next day i drove it back thinking it would be ok (preston audi said it should be ok if there was no lights on the dash) it didnt feel as smooth as it should of been, driving past stafford and the engine light came on, which i was told was the emissions light. Everytime i put my foot down or even slightly down a cloud of black smoke would come out of the exhaust. i didnt want to risk it so i called direct line and got picked up and taken to there yard. was hoping to take it to stafford audi but they couldn't fit me in at all..told there was nothing they could do. they couldn't figure out what the problem was so i drove it back slowly and now it's parked up on my drive until i take it to audi. now i no the turbo whistling sound is loud but now it's even louder, and some say theres sound like a police siren and i swear my sounds the same when driving at a slow speed and getting louder the faster i drove. what could be the possible causes before i get ripped off by audi? if i need a new turbo...well i don't even wanna think about that.