My best Sprinter bitch was the driver side window....
Driving doe the freeway one day, the driver side window (which was rolled up at the time) simply disappeared down into the door. It was an instantaneous thud and gone.
The window regulator mechanism had pretty much disintegrated. Once one rivet let loose gravity took over. Thankfully it was still under warranty at the time.... Took two days to fix as the door was taken apart while the waited for parts.
On the bright side, we get fantastic MGP.... Over 20 fully loaded. And I'm becoming pretty proficient as fixing things on the beast myself. Oh yah, the check engine light works great!
I'm Not an engineer, but I play one on TV. My handle is Tweety but I have nothing to do with the organization of similar name. I just had a really big head as a child so folks called me tweety bird.