Hi Guys.

My understanding is that all w220 have "double glazing". This glass is made of two layers of tempered safety glass with a plastic interlayer just like a (laminated) windshield.

The purpose of the double glazeing is to reduce outside noise but it also offers:-

1. extra protection from vandals/theft since unlike the normal side window glass it doesn't shatter into many pieces when hit with an onject like a centre punch.

2. better resistance to fogging due to insulating interlayer but this is marginal.
It does however offer the possibility of adding a heating element in the interlayer which would completely eliminate any fogging (offered as an option on the front screen by some manufacturers). Not aware of this being offered by anybody however on the side windows.
Auto Air con should keep windows from fogging anyway.

I believe that this glass structure is only used in conjunction with side air cushions since unlike conventional saftyglass, which is designed to shatter and thus reduce injury, this glass can present shards held in place by the interlayer which can cause injury under certain circumstances.

Stuart

 

You're right, BMW did have some bullet-proof 740iL and 750 iLs. But at the same time, Mercedes came up with the S-class GUARD Series, which looks like a regular S-class except for extra layers of poly-carbonate on the windows, amored fuel tank, and run-flat tires. In addition, Mercedes compensated the extra bulk with a meatier engine.