Since I don't have any diagnostic tools of my own I took the car to the Chrysler dealership in town. They just left me a message saying the problem is in the screem unit. The message said they need to order it from the Mercedes dealership at a cost of $635. Add 3 hours of labor and their total estimate comes to $1028.

1. can these screem units be fixed? By who and at what cost??
2. my car was not exhibiting the symptoms for screem failure that I've been reading about. (start briefly and shut down 2 times and nothing on 3rd try). Should I be concerned that the problem might be mis-diagnosed??