I don't have a Mercedes but my Jeep Cherokee Trailhawk has this same functionality and I did a cross country trip through northern america for the holidays. On

I don't have a Mercedes but my Jeep Cherokee Trailhawk has this same functionality and I did a cross country trip through northern america for the holidays. On mine at least it says something like "Sensor obscured, adaptive cruise control/lane keeping disabled. Please wipe off sensors." as well as making an audible ding to alert me to the message in my dash display.