It is interesting to know that the reason there is only one high intensity rear fog lamp is so drivers following are not confused with two that could be brake lights.
The positions of the switch for the lights, turning counter clockwise, are for parking. They are so your car is visible to traffic, but won't wear down your battery overnight, such as leaving all four of your parking lights on would. The left sidelights position is when you are parked on the right side of the road, and visa-versa.
In the ends of both rear doors are slots, near where the door lock/latch is found. Using a key I believe, will allow you to flip a latch that will prevent the inside door latches from working. A child safety thing.
The windshield washer fluid is heated. This of course prevents freezing in the winter and clears windshields rapidly, but in the summer, hot windshield washer fluid clears bugs much more effectively.
Older cars really benefit from a simple, easy to do, replacement of the front and rear sway bar bushings. On the 124s it only takes an hour, front and rear. Be sure to see whether your rear sway bar links need replacing as well. Your car will corner flatter and feel more in control. You can order them from this site or from a dealer.
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)