It never stops even after 84 years !!... Two problems on our W240 C Class CGI Turbo Cars. One sorted by the Internet information. The C 250 was sluggish compared to our C 200. Reset the ECU by disconnecting the Negative Terminal for 15 minutes. It resets itself going back to how it left the Factory. A very noticeable lift in performance up through the gears. Second issue was that the C.D. insert window would not open to insert a Disc. I recalled having to hold a button down for a few seconds to do something else. Held the eject button down and then hit select on the main control knob. A result. Tricks of the trade i hear you say.