Broken door contact switch W210
 

I was getting out of my car last night, and heard a terrible sound as I shut the door. The seat belt buckle had gotten between the door and the B-pillar, and shattered the door contact switch. At first I thought that the sound was just the buckle being crammed into the latch, but when the interior lamp wouldn't extinguish, I knew something else was up.

I took the switch out of the rear door as an emergency measure, as I really do like the car telling me to turn the headlights off when I get out. Good thing these switches are dirt cheap. I'm going to get an extra when I'm at the dealer.