Hi RadThad,
Welcome to Benzforum. I am not aware of any Driver/Owners manual that is available by download, but a similar question came up recently regarding where to obtain a Owners Manual and this is the response posted by AJCrowe:
"You might want to give Mercedes-Benz USA a call and purchase a owners manual. The publications department can mail you a manual for your vehicle. There is a charge but it is worth it to have the manual."
Also, if you are looking for a repair manual, Chilton and Haynes both make a pretty good repair manual at a reasonable price.
Again, welcome to the forum.
Ken