I bought this car as pre-owned from a Nissan dealer with an extended warranty. My heater/AC stopped blowing when I turn on the fan switch from 1-5. They replaced a part they had to order from Mercedes and it worked for 2 weeks. Now its not working again and I am being told that my extended warranty doesnt cover the part 2 times and now I have to go drive to Plano Texas (which is a 3 hour drive) a Mercedes dealer and have them look at it. In the meantime I am freezing with no heat, any help here please!!