Purchased a 96 E320 for an unbelievable deal. Here's the catch, all the windows not working, signal flashers, sunroof, seat adjustments, emergency flasher and side view mirrors. Everything else works like brand new, headlights, parking lights, dome lights, foglights, stereo and light in the instruments. Is there a central unit that relates to all that is not functioning? Please advise before I take it to an independent shop. Thank you....