Not planned as such, but I made a long non-stop road trip recently in my CLX. When I reached home I found that I had driven 410 miles in about 7 hours. The MB comfort had made it an easy task.
Later I realised that it must be the longest continuous drive I have ever made. No fuel stops, no comfort stops. I had some sandwiches and some drinking water onboard to keep me going.
However, I'm sure that others can beat this.