In Canada - me too
I had the same problem on my 560sel, but I solved the problem a little differently. My fuel distributor acted up every couple of weeks. Each time, we took the filter screens out of each line to the injectors and cleaned them. The car worked good for a while - then - rough idle again. Problem was rusty fuel lines - so bad that when we took them out, the weight of them broke the fuel line in two where it bends up to the firewall on the drivers side. Replacing the lines and cleaning the filter screens solved the problem. (3 months and counting) Hope this helps someone else. The fuel lines were cheap - replacing them was a pain!!