So I'm driving down the interstate here in South Jersey cruising around 75 miles an hour in my 2008 A6. All of a sudden my car seems to lose power and the engine starts to shake and sputter, then cuts off. Lucky I was able to immediately work my way from the far left lane to the shoulder and out of harm's way. I have no idea how I was able to do that without being rear ended or causing an accident. Anyway, I had the car towed to the local Audi dealer and I just received the call from the Service Manager. They found that there was low compression and in investigating found a shattered spark plug. The spark plug was shattered by a broken valve. The engine is blown! The strange thing is, I did not receive any prior notice or warnings that there was a potential catastrophic problem. No check engine light. No strange noises (ticking or knocking). No previous loss of power. No nothing. The car has 48,000 miles on it and it has been serviced by this dealership almost obsessively since purchased as a CPO. Needless to say that the engine is being replaced by Audi under warranty. I'm told that they are replacing it with a new engine. The question that goes out to the great members of the board is what concerns should I have withan engine replacement? What should I be looking for? What cautions should I take if any?