ez pass
basically the only Unshielded areas are the black dotted areas to the left and right of the rear view mirror , and a small square at the bottom
see here
https://mbworld.org/forums/s-class-w220/239745-radar-detector-location.html
If running out of real estate, sunroof is another option.
I was starting to think there was something up with the windshield when the transponder worked in my ML, and didn't in the S the next day.
Thank you for posting this!!!!










