On my W203 Coupe, I've found out how to find some 'hidden' display info. One of these is the oil volume, however, what are the other values listed in this same screen? I got to this by switching to ignition position 1, scrolling to mileage, then pressing the reset button 3 times. The other thing is that the same screen displays 'OM611' - is this as in OM611 engine? If it is then this is odd/wrong - my car has an OM646! Are there any other hidden displays? I also found VIN nr, something to do with the ESP and also found my way to the screen to reset the various service options/oils used.