I am wondering if my experience with my cruise control is normal. I have a 1993 300e. The "problem" occurs when the car is going down a relatively steep hill. Every 3 seconds or so, the cruise control will disengage and then engage a few seconds later. Each time it disengages, it is a very abrupt change, very noticeable. My last car never had this, the cruise control was very smooth. Is this a normal experience with MB cruise controls...