Some of the interior lights don't work, like the switch to turn on the headlights and also the passenger side air vent control as well as the buttons for the seat controls on the door panel. They work sometime after I drive on a really bumpy road but then they turn off after starting the car again usually. Any tips or thoughts would be greatly appreciated.

 

I have not had your symptoms in any Benz, however over the years in other vehicles the wiring sheath has been the cause of many issues. After the 600 having an extensive wiring harness problems I now look over wiring , connections, fuse blocks with a new set of critical issues. If fuses burn out, I look for "weld" marks where wires pass over vehicle frame areas. If switches stop working I also look at the wiring connected to the device. True most often the switch is bad but in a few times the sheath was broken. Hope you solve the failure.