I bought my car from a dealership in 2009. It's an one-year-old ex-demo with low mileage. No problems with previous service history. This year in Feb it started having problems. The engine indicator lights came on, which needed replacement of air flow sensor. Then, a few weeks later, the same problem and the sensor was replaced again. Then generalised poor power, but the main problem was complete loss of power at high speeds without warning - e.g. it suddenly can only go at 45mph on motorway. They have now completely replaced the turbo component, but agree that the car still does not drive properly. I'm in contact with customer services and the car has now been in the dealership's garage for one month. We are losing patience as we're constantly being told that more tests are being run. Please can you advise what more we can do and how much longer we have to wait?