My A4 is coming to 2 years old in January 2010 an has only done 20,000 miles. I lost the power and took it into Audi. They gave me a replacement car, which is great, but I am missing my car. They have changed the turbo, valves and it is still not the same, nothig is also coming up on the onboard computer system. What if they can not fix it? What heppns and what do I do?