I have checked haynes.com but it seems like they only cover C230 - C350. Any other good sources to check? I have tried to contact Mercedes-Benz Europe directly via e-mail for a regular manual, but they haven't answered that now in 4 weeks, so a question on repair manual seems to be in vain.
Mercedes Benz repair manuals are very well kept by the company. Haynes or any other repair manual providers usually don't touch upon these vehicle. The reason is due to the complexity of the the vehicles systems.
Also, replacing any modules require the
Mercedes Benz puts a lot of work into developing their vehicles. They don't want anyone except trained mechanics working on them.