This is a very interesting discussion. I ahve a new MB E220d with NTG 5.5. W213 and I cannot insert any POI into the navigation system. There is not any menu or option which let me to insert any POI. I contacted to official service and they told me that it is not possible. For sure, I don't believe this.
I don't know if the problem is in the name of the file, the format of SD card, etc... I have tried with FAT32 format, with PersonalPOI name and GPX files, but it doesn't work.
Recently I have discovered that official upgrade of Nav system has to be done with NTFS, otherwise NAV doesn't recognice the software. I tried to use PersonalPOI folder with GPX files (NTFS format in USB) but it doesn't work.
Do you know anything about the NTG 5.5 command online POI's?.
POI's doesn't work with MB command online W312
