Help! fix seat switch knob E420
 

Has anyone broken AND repaired the seat switch on the driver's side door. Some time ago, I gently (I thought) pried off the lower (seat bottom) knob on the switch and broke the square plastic protrusion that the knob snaps onto. That piece of plastic looks replaceable but not easily and so, I doubt that the piece is available. But over $100 for a new switch!!! And it works fine. Anybody been down this road?

Do you still have the broken off square protrusion (maybe still in the back of the seat lever)? If so, you may be able to use a TINY amount of superglue such as 'plastic surgery' brand and re-attach the button without messing up the switch.

If you don't have the square section, I have repaired other plastic switches by inserting a small and short metal screw (a little bigger than eyeglass screws) into the broken off area, without going too deep and shorting out the switch. This leaves a peg like protrusion that a dab of 2 part epoxy on the back of the switch can grip. Takes patience and a steady hand. Good luck.