Would you say this is true even on the CAN equipped cars? MB Doc seemed to say these motors/modules were a weak point on those.

In my experience YES, but he has more experience, so.....
I would add that it is usually fairly obvious, if the owner is mechanically inclined at all, that the regulator is busting (as prior post said, crunching or other odd noises), definitely know there is something mechanically undue happenin', not like when you have a motor or switch go out and suddenly the window doesn't work.

Here is a link to the type of rivet gun we had for doing these large rivets:
http://www.restockit.com/The-Big-Daddy-Riveter-w-Extended-Nose-Piece-(MAR39035).html?source=froogle&Bvar5=100F1&Bvar6=100F1&Bvar7=100F1

Thank you very much Mpolli. Gilly, I don't think its my regulator because it just suddenly stopped working, no noises, sluggishness or other irratic operation...it just stopped working. I guess I will know once I pull the door panel off. Like I said before, I have replaced power window motors and regulators before, just not on the MB. None of the ones that I have done before required rivets. One more quick question. Does the door panel have special clips or snaps that need to be replaced?

I just replaced the regulator on a friends 2000 E320 and removed the motor before removing the regulator.
The door panel is held on by clips and some of them may not be reusable. I replaced 3 at a cost of $1.50 each from the dealer.

Mine kind of stopped and started like yours. One day it worked, another it didn't. Then one day it went down and wouldn't go back up. It seems to me that I got an aftermarket motor and the rest of it for like $90 shipped. While it was cheaper they did send me the wrong side first.

Anyway, there was a video of a factory tech that I found somewhere. It was supposedly off the DVD. There are also pretty good pics if you search on this site as well. Of course there's also the MB W210 Door Trim Removal tool. I think it costs $10 but it is basically a round tipped flat piece of plastic that gets thicker towards the top. After you removed all the screws in the door just slip the thin end of the tool in and move around the door till it stops. Twist till you hear a pop and move onto the next one.

The first rivet broke my rivet gun so i went with stainless screws and nylon (airplane) nuts so they wouldn't shake loose.

See the W210 Front Door Panel Removal article on the DIY tab above. While not the same as the rear it is VERY similar.

Here's the DIY for the rear door w/ pics. Sorry, it's from the "other" site.

http://www.benzworld.org/forums/w210-e-class/1226700-diy-pictorial-window-regulator-replacement.html