As with any convertible, they have more noises than a hardtop. Dry seals are usually the culprit, and are the first place to start. There is a fairly new rubber lube that I believe was especially put out wfor the SLK'a. I use it on weatherstrips for all car, and it works great. It comes in a little tube, and you can ask your local factory dealership to use it on your car. I can get the part number if you don't have any luck on your own.