How likely is it that the Steering Dampener and Motor Mounts require replacement at 46,000 miles on a 1999 C280 Sport? While the dealer is the largest around, I'm a little suspicous that they see problems before they really exist. I would expect to "feel" vibrations if they are failing, but don't really notice anything. Any thoughts? In addition, what would be an educated guess to repair replace the steering dampener and motor mounts?

Thanks!