Mercedes-Benz is known around the world for producing powerful luxury automobiles. The C-Class is at the front of the German auto manufacturer’s line of smaller sized sedans. The W203 remains an agile and stylish sedan, but is smaller and therefore more fuel efficient than other vehicles produced by the company. Even so, sometimes issues do make themselves known and need the attention of a professional mechanic.
One problem that people do complain of that is perhaps not unique to the Mercedes-Benz W203, is the problem of suspension noises. Squeaks, squeals and clunks -- all these noises can seem to be emanating from the suspension, but it's very difficult to be sure of the cause as well as the origin. If the source of the noise is difficult to ascertain, then it has been recommended by some C Class owners, that the application of a silicone based spray to the general area may reduce the noise.
This would be an easy fix and an inexpensive one if it works, however, this is sort of a Hail Mary pass in terms of the effectiveness of the outcome. You may find that a water resistant spray does do the trick, but if you've tried this or similar methods of dealing with the issue, and you still have unidentifiable noises, then it's time to take your car to a professional.
If you are hearing noises that may be related to the suspension of your Mercedes-Benz C-Class, it is always a good idea to take your car in to a trained German Import technician. You need to get a proper diagnosis so that a repair plan can be put into place.
Search for a local, independent Mercedes-Benz repair shop with Mercedes-Benz mechanics that have dealer-level expertise at a fraction of the expense.