Analog Tele Aid units are no longer supported and must be updated to digital, preferably at a dealership or a well-equipped independent shop. The update and all related factors should be completed at the same time.Google+
Car Problem Reports
Mercedes-Benz S500 Analog Tele Aid Units Are no Longer Supported
Mercedes-Benz S500 Problem
The early CD-based navigation CD's are no longer available either. The stereo system unit in the dash in 2000-2002 cars is not a standard size that can be replaced with a new stereo, and the factory Bose amp in the trunk, and CD changer in the trunk, use a fiber optic system that is propritary to this car. In short, if you buy a 2000-2002 model, make sure you can just live with the factory system. It CAN be updated or changed if cost is no object (if you're capable, there are tips and instructions on the web from people who have claimed to do it, or a big city may have capable stereo shops), but this is not something your local Best Buy or Radio Shack can probably do for you. I use a cassette adapter for my iPod, which works fine for me, though my kids think it's hilarious, or I just burn CD's from my iTunes and put them in the CD changer.