About the delamintion?
 

I know all W126 have the delamination problem, but where do I buy a new rear window? The Mercedes dealer? how much will it run me and is it a DIY?

I would think you'd be best off just buying a used rear window as it seems like the stealer really lives up to their name on that part! Changing the window can be done as a DIY, it is good to have a helper work with you. Rope is used to seat the new seal in place, I've never done it but there are several here who have.

Window:
 

If you buy a used window.
Please inspect the heating elements for cuts. If there are brakes in the heating element it won't work.
Next when the window is out inspect for rust around the rear window. They are prone to have some.
And I would use new rubber for rear window.
Also some pick ur parts out here have a guy there that does glass. You might ask how much to install.
Good luck.
Charlie

Glass removal is harder than you'd think.

I do ALMOST all of the work on my cars. The exception is anything that has to do with the front or rear glass. Last fall, I tried to remove my 300D's front windsheld, carefully doing all the things shown in the FSM and still managed to crack it.

Original glass on the 20+ year old cars is virtually FUSED to the gasket and the gasket is practically FUSED to the body of the car. IMHO, it is something best left to the pros...provided that they know without a doubt how these cars come apart.

Make sure they know that the trim comes out with the gasket. Make sure that they know to be careful with the rear defogger wires (Harmon hosed the ones on Lilly!!).

Here's some other info:
http://www.peachparts.com/shopforum/diesel-discussion/81088-need-1982-300d-windshield-help.html?highlight=glass[/url]

I agree that the rear windshield isn't cake but I'm quite confident I could do it if I had to. The front windshield is a good deal harder than the rear, if I have my 83 long enough I'll end up giving it a try as the factory windshield doesn't look very nice.