Unless you are seeking the armor for actual use, and have pockets as deep as a mighty ocean, I encourage you to review your options.
Factory armored cars and aftermarket armored cars universally lose the ability to see out of the heavily clad windows as the vehicle ages. Already compromised due to the 2" + thickness of laminated glass, the lamination begins to yellow due to chlorine leach as the materials used to bond the layers of glass and plastic begin to degrade.
Look at a 15 year old car with plastic headlights, and then imagine all four side windows of an automobile being in that condition - and due to the multiple layers they can neither be restored nor replaced. Nobody makes laminate armored glass anymore as polycarbonate is 1/4 the weight and thickness with similar protection.
With a similar amount of money you can purchase an investment-grade W116 450SEL 6.9, a vehicle that is legendary for brute force, indestructibility and serious gangster cred.
Please somebody, I don't have time - could someone please post the Ronin and Lost Horizon clips for this new enthusiast?
If true armor is what you want and need, I believe the W140 series from 1990 - 2000 would be the ticket. Due to the already super thick nitrogen filled glass on the top line models, the S-class with armor is both serviceable AND you can expect the glass to stay clear. Also, with the high velocity rounds now common in any serious attack, you must be made aware that the W116 with factory armor wouldn't pass even the lowest modern standard - but the W140 will.
I look forward to how this comes out - as you can find armor if that is your heart's desire. I wasn't expecting the Sultan of Brunei to become a member (and it would take his wallet to replace the glass).