I found this on another MB discussion group. If anyone knows of more such features, please do share with the rest.

"I used to check the MBCanada forum site which has disappeared. But the one post that i regret not printing was the one with features that are not known to many and not printed anywhere either. Below is an example. If you know of any, please add to this and maybe we could have a pretty good collection which could be used by all of us.

Scenario. Your window's half open. Passenger fully open. Moonroof (on tilt), rear passengers open just a bit. You see a smoke cloud ahead and don't want it to enter the car. Hold down the "Recirculate (Car with circle button on Climate control)" button for a couple of seconds and all windows and roof closes. But that's not the gem. Once you're out of the area, hold down the same "Recirculate" button again and all windows and roof return to their original positions prior to closing it."

 

The Hidden Feature is not and does not work in My 1995 E320 and 1999 E320.