I am not an expert on the matter, but I will definitely avoid towing the car, especially at speeds above 30 mph.
All the Mercedes Benzes I owned advise on the owner's manual NOT to tow the car with an automatic transmition.
There are some footnotes on the manuals about extreme situations where you may tow the car for very short distances and at very low speeds. The rest of time a platform tow-truck is strongly recommeded, or you may risk high and expensive damage.
S 320 1998
E 320 T 1995