I have a friend who owns an S420 (don't know the year) that he claims has bullet-proof glass. I don't know from bullet-proof, but the side glass is about 1/4" thick and has a thin lip to fit the gasket groove. It's mirrored, but I can't tell if it's OE or after market. This is obviously some sort of special glass, but what kind? On that note, if the glass is bullet-proof, would the car necessarily be armored as well? It's a clapped-out POS with 320k miles that he has let run down hill from there, but it's not my car or my problem. I'm just curious. Any help would be appreciated.