This seems to be fairly hard to find. It has something to do with a moratorium that MB has on manuals (up to three years?). I've searched for a manual on my '98, but ended up getting a subscription on:
http://www.alldatadiy.com
, which is mediocre. It has parts, locations, and instructions, but little on diagnosing or general instructions. I'm used-to the haynes manuals that give you much more detailed information.
Good luck, I'll be watching to see if something better comes up.
Don