Mercedes-Benz M-Class 2006 Owners Manual - Manual (Page 297)

296
Controls in detail
Useful features
Zone map South America
Infrared reflecting windshield*
1 Mounting location for electronic toll
collection devices (infrared transpar-
ent)
Your vehicle is equipped with infrared re-
flecting glass which reduces the amount of
radiated heat entering the interior through
the windows.
The infrared reflecting glass also prevents
the transmission of signals through the
glass by in-vehicle electronic devices (e.g.
electronic toll collection devices).
To allow the use of these devices in the
vehicle, two infrared transparent areas
(
1 and 2) are placed in the windshield.