One problem related to starter relay has been reported for the 2001 Mercedes Benz 320. The most recently reported issues are listed below.
Various problems with electrical, heating and cooling, suspension, power steering, lighting, and purge valve systems. Spent 7k in last 3 years alone. Heating and cooling system was removed and reinstalled twice and still does not work right. Struts and steering system completely brakes down every 6 months. I am in the repair shop every 2-3 months! average out of pocket (after extended warranty) $500. . . Outrageous (x4 or 5 per year!). Warranty kicks in another 4k per year. My records show 14 visits to mercedes repair shops since November 2004. . . Insane. This is my first and last mercedes! even my service adviser told me to get a Lexus or Acura!.